Developing Trading Strategies With Synthetic Data

One of the main criticisms levelled at systematic trading over the last few years is that the over-use of historical market data has tended to produce curve-fitted strategies that perform poorly out of sample in a live trading environment. This is indeed a valid criticism – given enough attempts one is bound to arrive eventually at a strategy that performs well in backtest, even on a holdout data sample. But that by no means guarantees that the strategy will continue to perform well going forward.

The solution to the problem has been clear for some time: what is required is a method of producing synthetic market data that can be used to build a strategy and test it under a wide variety of simulated market conditions. A strategy built in this way is more likely to survive the challenge of live trading than one that has been developed using only a single historical data path.

The problem, however, has been in implementation. Up until now all the attempts to produce credible synthetic price data have failed, for one reason or another, as I described in an earlier post:

I have been able to devise a completely new algorithm for generating artificial price series that meet all of the key requirements, as follows:

  • Computational simplicity & efficiency. Important if we are looking to mass-produce synthetic series for a large number of assets, for a variety of different applications. Some deep learning methods would struggle to meet this requirement, even supposing that transfer learning is possible.
  • The ability to produce price series that are internally consistent (i.e High > Low, etc) in every case .
  • Should be able to produce a range of synthetic series that vary widely in their correspondence to the original price series. In some case we want synthetic price series that are highly correlated to the original; in other cases we might want to test our investment portfolio or risk control systems under extreme conditions never before seen in the market.
  • The distribution of returns in the synthetic series should closely match the historical series, being non-Gaussian and with “fat-tails”.
  • The ability to incorporate long memory effects in the sequence of returns.
  • The ability to model GARCH effects in the returns process.

This means that we are now in a position to develop trading strategies without any direct reference to the underlying market data. Consequently we can then use all of the real market data for out-of-sample back-testing.

Developing a Trading Strategy for the S&P 500 Index Using Synthetic Market Data

To illustrate the procedure I am going to use daily synthetic price data for the S&P 500 Index over the period from Jan 1999 to July 2022. Details of the the characteristics of the synthetic series are given in the post referred to above.

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Because we want to create a trading strategy that will perform under market conditions close to those currently prevailing, I will downsample the synthetic series to include only those that correlate quite closely, i.e. with a minimum correlation of 0.75, with the real price data.

Why do this? Surely if we want to make a strategy as robust as possible we should use all of the synthetic data series for model development?

The reason is that I believe that some of the more extreme adverse scenarios generated by the algorithm may occur quite rarely, perhaps once in every few decades. However, I am principally interested in a strategy that I can apply under current market conditions and I am prepared to take my chances that the worst-case scenarios are unlikely to come about any time soon. This is a major design decision, one that you may disagree with. Of course, one could make use of every available synthetic data series in the development of the trading model and by doing so it is likely that you would produce a model that is more robust. But the training could take longer and the performance during normal market conditions may not be as good.

Having generated the price series, the process I am going to follow is to use genetic programming to develop trading strategies that will be evaluated on all of the synthetic data series simultaneously. I will then use the performance of the aggregate portfolio, i.e. the outcome of all of the trades generated by the strategy when applied to all of the synthetic series, to assess the overall performance. In order to be considered, candidate strategies have to perform well under all of the different market scenarios, or at least the great majority of them. This ensures that the strategy is likely to prove more robust across different types of market conditions, rather than on just the single type of market scenario observed in the real historical series.

As usual in these cases I will reserve a portion (10%) of each data series for testing each strategy, and a further 10% sample for out-of-sample validation. This isn’t strictly necessary: since the real data series has not be used directly in the development of the trading system, we can later test the strategy on all of the historical data and regard this as an out-of-sample backtest.

To implement the procedure I am going to use Mike Bryant’s excellent Adaptrade Builder software.

This is an exemplar of outstanding software engineering and provides a broad range of features for generating trading strategies of every kind. One feature of Builder that is particularly useful in this context is its ability to construct strategies and test them on up to 20 data series concurrently. This enables us to develop a strategy using all of the synthetic data series simultaneously, showing the performance of each individual strategy as well for as the aggregate portfolio.

After evolving strategies for 50 generations we arrive at the following outcome:

The equity curve for the aggregate portfolio is shown in blue, while the equity curves for the strategy applied to individual synthetic data series are shown towards the bottom of the chart. Of course, the performance of the aggregate portfolio appears much superior to any of the individual strategies, because it is effectively the arithmetic sum of the individual equity curves. And just because the aggregate portfolio appears to perform well both in-sample and out-of-sample, that doesn’t imply that the strategy works equally well for every individual market scenario. In some scenarios it performs better than in others, as can be observed from the individual equity curves.

But, in any case, our objective here is not to create a stock portfolio strategy, but rather to trade a single asset – the S&P 500 Index. The role of the aggregate portfolio is simply to suggest that we may have found a strategy that is sufficiently robust to work well across a variety of market conditions, as represented by the various synthetic price series.

Builder generates code for the strategies it evolves in a number of different languages and in this case we take the EasyLanguage code for the fittest strategy #77 and apply it to a daily chart for the S&P 500 Index – i.e. the real data series – in Tradestation, with the following results:

The strategy appears to work well “out-of-the-box”, i,e, without any further refinement. So our quest for a robust strategy appears to have been quite successful, given that none of the 23-year span of real market data on which the strategy was tested was used in the development process.

We can take the process a little further, however, by “optimizing” the strategy. Traditionally this would mean finding the optimal set of parameters that produces the highest net profit on the test data. But this would be curve fitting in the worst possible sense, and is not at all what I am suggesting.

Instead we use a procedure known as Walk Forward Optimization (WFO), as described in this post:

The goal of WFO is not to curve-fit the best parameters, which would entirely defeat the object of using synthetic data. Instead, its purpose is to test the robustness of the strategy. We accomplish this by using a sequence of overlapping in-sample and out-of-sample periods to evaluate how well the strategy stands up, assuming the parameters are optimized on in-sample periods of varying size and start date and tested of similarly varying out-of-sample periods. A strategy that fails a cluster of such tests is unlikely to prove robust in live trading. A strategy that passes a test cluster at least demonstrates some capability to perform well in different market regimes.

To some extent we might regard such a test as unnecessary, given that the strategy has already been observed to perform well under several different market conditions, encapsulated in the different synthetic price series, in addition to the real historical price series. Nonetheless, we conduct a WFO cluster test to further evaluate the robustness of the strategy.

As the goal of the procedure is not to maximize the theoretical profitability of the strategy, but rather to evaluate its robustness, we select a criterion other than net profit as the factor to optimize. Specifically, we select the sum of the areas of the strategy drawdowns as the quantity to minimize (by maximizing the inverse of the sum of drawdown areas, which amounts to the same thing). This requires a little explanation.

If we look at the strategy drawdown periods of the equity curve, we observe several periods (highlighted in red) in which the strategy was underwater:

The area of each drawdown represents the length and magnitude of the drawdown and our goal here is to minimize the sum of these areas, so that we reduce both the total duration and severity of strategy drawdowns.

In each WFO test we use different % of OOS data and a different number of runs, assessing the performance of the strategy on a battery of different criteria:

x

These criteria not only include overall profitability, but also factors such as parameter stability, profit consistency in each test, the ratio of in-sample to out-of-sample profits, etc. In other words, this WFO cluster analysis is not about profit maximization, but robustness evaluation, as assessed by these several different metrics. And in this case the strategy passes every test with flying colors:

Other than validating the robustness of the strategy’s performance, the overall effect of the procedure is to slightly improve the equity curve by diminishing the magnitude and duration of the drawdown periods:

Conclusion

We have shown how, by using synthetic price series, we can build a robust trading strategy that performs well under a variety of different market conditions, including on previously “unseen” historical market data. Further analysis using cluster WFO tests strengthens the assessment of the strategy’s robustness.

Long/Short Stock Trading Strategy

The Long-Short Stock Trader strategy uses a quantitative model to introduce market orders, both entry and exits. The model looks for divergencies between stock price and its current volatility, closing the position when the Price-volatility gap is closed.  The strategy is designed to obtain a better return on risk than S&P500 index and the risk management is focused on obtaining a lower drawdown and volatility than index.
The model trades only Large Cap stocks, with high liquidity and without scalability problems. Thanks to the high liquidity, market orders are filled without market impact and at the best market prices.

For more information and back-test results go here.

The Long-Short Trader is the first strategy launched on the Systematic Algotrading Platform under our new Strategy Manager Program.

Performance Summary


 

Monthly Returns

 

Value of $100,000 Portfolio

 

 

 

 

Career Opportunity for Quant Traders

Career Opportunity for Quant Traders as Strategy Managers

We are looking for 3-4 traders (or trading teams) to showcase as Strategy Managers on our Algorithmic Trading Platform.  Ideally these would be systematic quant traders, since that is the focus of our fund (although they don’t have to be).  So far the platform offers a total of 10 strategies in equities, options, futures and f/x.  Five of these are run by external Strategy Managers and five are run internally.

The goal is to help Strategy Managers build a track record and gain traction with a potential audience of over 100,000 members.  After a period of 6-12 months we will offer successful managers a position as a PM at Systematic Strategies and offer their strategies in our quantitative hedge fund.  Alternatively, we will assist the manager is raising external capital in order to establish their own fund.

If you are interested in the possibility (or know a talented rising star who might be), details are given below.

Manager Platform

Volatility Trading Styles

The VIX Surge of Feb 2018

Volatility trading has become a popular niche in investing circles over the last several years.  It is easy to understand why:  with yields at record lows it has been challenging to find an alternative to equities that offers a respectable return.  Volatility, however, continues to be volatile (which is a good thing in this context) and the steepness of the volatility curve has offered investors attractive returns by means of the volatility carry trade.  In this type of volatility trading the long end of the vol curve is sold, often using longer dated futures in the CBOE VIX Index, for example.  The idea is that profits are generated as the contract moves towards expiration, “riding down” the volatility curve as it does so.  This is a variant of the ever-popular “riding down the yield curve” strategy, a staple of fixed income traders for many decades.  The only question here is what to use to hedge the short volatility exposure – highly correlated S&P500 futures are a popular choice, but the resulting portfolio is exposed to significant basis risk.  Besides, when the volatility curve flatten and inverts, as it did in spectacular fashion in February, the transition tends to happen very quickly, producing a substantial losses on the portfolio.  These may be temporary, if the volatility spike is small or short-lived, but as traders and investors discovered in the February drama, neither of these two desirable outcomes is guaranteed.  Indeed as I pointed out in an earlier post this turned out to be the largest ever two-day volatility surge in history.  The results for many hedge funds, especially in the quant sector were devastating, with several showing high single digit or double-digit losses for the month.

VIX_Spike_1

 

Over time, investors have become more familiar with the volatility space and have learned to be wary of strategies like volatility carry or option selling, where the returns look superficially attractive, until a market event occurs.  So what alternative approaches are available?

An Aggressive Approach to Volatility Trading

In my blog post Riders on the Storm  I described one such approach:  the Option Trader strategy on our Algo Trading Platform made a massive gain of 27% for the month of February and as a result strategy performance is now running at over 55% for 2018 YTD, while maintaining a Sharpe Ratio of 2.23.

Option Trader

 

The challenge with this style of volatility trading is that it requires a trader (or trading system) with a very strong stomach and an investor astute enough to realize that sizable drawdowns are in a sense “baked in” for this trading strategy and should be expected from time to time.  But traders are often temperamentally unsuited to this style of trading – many react by heading for the hills and liquidating positions at the first sign of trouble; and the great majority of investors are likewise unable to withstand substantial drawdowns, even if the eventual outcome is beneficial.

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The Market Timing Approach

So what alternatives are there?  One way of dealing with the problem of volatility spikes is simply to try to avoid them.  That means developing a strategy logic that step aside altogether when there is a serious risk of an impending volatility surge.  Market timing is easy to describe, but very hard to implement successfully in practice.  The VIX Swing Trader strategy on the Systematic Algotrading platform attempts to do just that, only trading when it judges it safe to do so. So, for example, it completely side-stepped the volatility debacle in August 2015, ending the month up +0.74%.  The strategy managed to do the same in February this year, finishing ahead +1.90%, a pretty creditable performance given how volatility funds performed in general.  One helpful characteristic of the strategy is that it trades the less-volatile mid-section of the volatility curve, in the form of the VelocityShares Daily Inverse VIX MT ETN (ZIV).  This ensures that the P&L swings are much less dramatic than for strategies exposed to the front end of the curve, as most volatility strategies are.

VIX Swing Trader1 VIX Swing Trader2

A potential weakness of the strategy is that it will often miss great profit opportunities altogether, since its primary focus is to keep investors out of trouble. Allied to this, the system may trade only a handful of times each month.  Indeed, if you look at the track record above you find find months in which the strategy made no trades at all. From experience, investors are almost as bad at sitting on their hands as they are at taking losses:  patience is not a highly regarded virtue in the investing community these days.  But if you are a cautious, patient investor looking for a source of uncorrelated alpha, this strategy may be a good choice. On the other hand, if you are looking for high returns and are willing to take the associated risks, there are choices better suited to your goals.

The Hedging Approach to Volatility Trading

A “middle ground” is taken in our Hedged Volatility strategy. Like the VIX Swing Trader this strategy trades VIX ETFs/ETNs, but it does so across the maturity table. What distinguishes this strategy from the others is its use of long call options in volatility products like the iPath S&P 500 VIX ST Futures ETN (VXX) to hedge the short volatility exposure in other ETFs in the portfolio.  This enables the strategy to trade much more frequently, across a wider range of ETF products and maturities, with the security of knowing that the tail risk in the portfolio is protected.  Consequently, since live trading began in 2016, the strategy has chalked up returns of over 53% per year, with a Sharpe Ratio of 2 and Sortino Ratio above 3.  Don’t be confused by the low % of trades that are profitable:  the great majority of these loss-making “trades” are in fact hedges, which one would expect to be losers, as most long options trades are.  What matters is the overall performance of the strategy.

Hedged Volatility

All of these strategies are available on our Systematic Algotrading Platform, which offers investors the opportunity to trade the strategies in their own brokerage account for a monthly subscription fee.

The Multi-Strategy Approach

The approach taken by the Systematic Volatility Strategy in our Systematic Strategies hedge fund again seeks to steer a middle course between risk and return.  It does so by using a meta-strategy approach that dynamically adjusts the style of strategy deployed as market conditions change.  Rather than using options (the strategy’s mandate includes only ETFs) the strategy uses leveraged ETFs to provide tail risk protection in the portfolio. The strategy has produced an average annual compound return of 38.54% since live trading began in 2015, with a Sharpe Ratio of 3.15:

Systematic Volatility Strategy 1 Page Tear Sheet June 2018

 

A more detailed explanation of how leveraged ETFs can be used in volatility trading strategies is given in an earlier post:

http://jonathankinlay.com/2015/05/investing-leveraged-etfs-theory-practice/

 

Conclusion:  Choosing the Investment Style that’s Right for You

There are different styles of volatility trading and the investor should consider carefully which best suits his own investment temperament.  For the “high risk” investor seeking the greatest profit the Option Trader strategy in an excellent choice, producing returns of +176% per year since live trading began in 2016.   At the other end of the spectrum, the VIX Swing trader is suitable for an investor with a cautious trading style, who is willing to wait for the right opportunities, i.e. ones that are most likely to be profitable.  For investors seeking to capitalize on opportunities in the volatility space, but who are concerned about the tail risk arising from major market corrections, the Hedge Volatility strategy offers a better choice.  Finally, for investors able to invest $250,000 or more, a hedge fund investment in our Systematic Volatility strategy offers the highest risk-adjusted rate of return.

Riders on the Storm

The Worst Volatility Scare for Years

February 2018 was an insane month for stocks, wrote CNN:

A profound inflation scare. Not one but two 1,000-point plunges for the Dow. And a powerful comeback that almost went straight back up.

The CNN story-line continues:

The Dow plummeted more than 3,200 points, or 12%, in just two weeks. Then stocks raced back to life, at one point recovering about three-quarters of those losses.

Fittingly, February ended with more drama. The Dow tumbled 680 points during the month’s final two days, leaving it down about 1,600 points from the record high in late January.

The headline in the Financial Times was a little more nuanced, focusing on the impact of the market turmoil on quant hedge funds:

 

FT

 

Quant Funds Get Trashed

The FT reported:

Computer-driven, trend-following hedge funds are heading for their worst month in nearly 17 years after getting whipsawed when the stock market’s steady soar abruptly reversed into one of the quickest corrections in history earlier in February.

The carnage amongst hedge funds was widespread, according to the article:

Société Générale’s CTA index is down 5.55 per cent this month, even after the recent market rebound, making it the worst period for these systematic hedge funds since November 2001.
Man AHL’s $1.1bn Diversified fund lost almost 10 per cent in the month to February 16, while the London investment firm’s AHL Evolution and Alpha funds were down about 4-5 per cent over the same period. The flagship funds of GAM’s Cantab Capital, Systematica and Winton lost 9.5 per cent, 7.2 per cent and 4.6 per cent* respectively between the start of the month and February 16. Aspect Capital’s Diversified Fund dropped 9.5 per cent in the month to February 20, while a trend-following fund run by Lynx Asset Management slumped 12.7 per cent. A leveraged version of the same fund tumbled 18.8 per cent. One of the other big victims is Roy Niederhoffer, whose fund lost 21.1 per cent in the month to February 20.

Painful reading, indeed.

 

Traders conditioned to a state of somnambulance were shocked by the ferocity of the volatility spike, as the CBOE VIX index soared by over 200% in a single day, reaching a high of over 38 on Feb 5th:

 

VIX Index

 

Indeed, this turned out to be the largest ever two-day increase in the history of the index:

VIX_Spike_1

This Quant Strategy Made 27% In February Alone

So, for a quant-driven options strategy that is typically a premium seller, February must surely have been a disaster, if not a total wipe-out.  Not quite.  On the contrary, our Option Trader strategy made a massive gain of 27% for the month.  As a result strategy performance is now running at over 55% for 2018 YTD, while maintaining a Sharpe Ratio of 2.23.

Option Trader

You can tell that the strategy has a tendency to collect option premiums, not only because the strategy description says as much, but also from the observation that over 90% of strategy trades have been profitable – one of the defining characteristics of volatility strategies that are short-Vega, long-Theta.  The theory is that such strategies make money most of the time, but then give it all back (and more) when volatility inevitably spikes.  While that is generally true, in my experience, that clearly didn’t occur here.  So what’s the story?

One of the advantages of our Algo Trading Platform is that it not only reports in detail the live performance of our strategies, but it also reveals the actual trades on the site (typically delayed by 24-72 hours).  A review of the trades made by the Option Trader strategy from the end of January though early February indicates a strongly bullish bias, with short put trades in stocks such as Netflix, Inc. (NFLX), Shopify Inc. (SHOP), The Goldman Sachs Group, Inc. (GS) and Facebook, Inc. (FB), coupled with short call trades in VIX ETF products such as ProShares Ultra VIX Short-Term Futures (UVXY) and iPath S&P 500 VIX ST Futures ETN (VXX).  As volatility began to spike on 2/5, more calls were sold at increasingly fat premiums in several of the VIX Index ETFs.  These short volatility positions were later hedged with long trades in the underlying ETFs and, over time, both the hedges and the original option sales proved highly profitable. In other words, the extremely high levels of volatility enabled the strategy to profit on both legs of the trade, a highly unusual occurrence.  Meanwhile, while it was hedging its bets in the VIX ETF option trades, the strategy was becoming increasingly aggressive in the single stocks sector, taking outright long positions in Baidu, Inc. (BIDU), Align Technology, Inc. (ALGN), Netflix, Inc. (NFLX) and others, just as they became trading off their lows in the second week of the month.  By around Feb 12th the strategy recognized that the volatility shock had begun to subside and took advantage of the inflated option premia, selling puts across the board, in particular in the technology (Tesla, Inc. (TSLA), NVIDIA Corporation (NVDA)) and retail sectors (GrubHub Inc. (GRUB), Alibaba Group Holding Limited (BABA)) that had suffered especially heavy declines.  Many of these trades were closed at a substantial profit within a span of just a few days as the market stabilized and volatility subsided.  The strategy broadened the scope of its option selling as the month progressed, initially recovering the entirety of the drawdown it had initially suffered, before going on to register substantial profits on almost every trade.

To summarize:

  1.  Like many other market players, the Volatility Trader strategy was initially caught on the wrong side of the volatility spike and suffered a significant drawdown.
  2. Instead of liquidating positions, the strategy began hedging aggressively in sectors holding the greatest danger – VIX ETFs, in particular.  These trades ultimately proved profitable on both option and hedge legs as the market turned around and volatility collapsed.
  3. As soon as volatility showed signed of easing, the strategy began making aggressive bets on market stabilization and recovery, taking long positions in some of the most beaten-down stocks and selling puts across the board to capture inflated option premia.

Lesson Learned:  Aggressive Defense is the best Options Strategy in a Volatile Market

If there is one lesson above all others to be learned from this case study it is this:  that a period of market turmoil is a time of opportunity for option traders, but only if they play aggressively, both in defense and offense.  Many traders run scared at times like this and liquidate positions, taking heavy losses in the process that can prove impossible to recover from if, as here, the drawdown is severe.  This study shows that by holding one’s nerve and hedging rather than liquidating loss-making positions and then moving aggressively to capitalize on inflated option prices a trader can not only weather the storm but, as in this case, produce exceptional returns.

The key take-away is this: in order to play aggressively you have to have sufficient reserves in the tank to enable you to hold positions rather than liquidate them and, later on, to transition to selling expensive option premiums.  The mistake many option traders make is to trade too close to the line in term of margin limits, resulting  in a forced liquidation of positions that would otherwise have been profitable.

You can trade the Option Trader strategy live in your own brokerage account – go here for details.

 

 

Trading Prime Market Cycles

Magicicada tredecassini NC XIX male dorsal trim.jpg

Magicicada is the genus of the 13-year and 17-year periodical cicadas of eastern North America. Magicicada species spend most of their 13- and 17-year lives underground feeding on xylem fluids from the roots of deciduous forest trees in the eastern United States.  After 13 or 17 years, mature cicada nymphs emerge in the springtime at any given locality, synchronously and in tremendous numbers.  Within two months of the original emergence, the lifecycle is complete, the eggs have been laid, and the adult cicadas are gone for another 13 or 17 years.

The emergence period of large prime numbers (13 and 17 years) has been hypothesized to be a predator avoidance strategy adopted to eliminate the possibility of potential predators receiving periodic population boosts by synchronizing their own generations to divisors of the cicada emergence period. If, for example, the cycle length was, say, 12 years, then the species would be exposed to predators regenerating over cycles of 2, 3, 4, or 6 years.  Limiting their cycle to a large prime number reduces the variety of predators the species is likely to face.

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Prime Cycles in Trading Strategies

What has any of this to do with trading?  When building a strategy in a particular market we might start by creating a model that works reasonably well on, say, 5-minute bars. Then, in order to improve the risk-adjusted returns we might try create a second sub-strategy on a different frequency.  This will hopefully result in a new series of signals, an increase in the number of trades, and corresponding improvement in the risk-adjusted returns of the overall strategy.  This phenomenon is referred to as temporal diversification.

What time frequency should we select for our second sub-strategy?  There are many factors to consider, of course, but one of them is that we would like to see as few duplicate signals between the two sub-strategies.  Otherwise we will simply be replicating trades, rather than reducing the overall level of strategy risk through temporal diversification.  The best way to minimize the overlap in signals generated by multiple sub-strategies is to use prime number bar frequencies (5 minute, 7 minute, 11 minute, etc).

S&P500 Swing Trading Strategy

An example of this approach is our EMini Swing Trading strategy which we operate on our Systematic Algotrading Platform.  This strategy is actually a combination of several different sub-strategies that operate on 5-minute, 11-minute, 17-minute and 31-minute bars.  Each strategy focuses on a different set of characteristics of the S&P 500 futures market, but the key point here is that the trading signals very rarely overlap and indeed several of the sub-strategies have a low correlation.

correl

 

The resulting increase in trade frequency and temporal diversification produces very attractive risk-adjusted performance: after an exceptional year in 2017 which saw a 78.58% net return, the strategy is already at  +60% YTD in 2018 and showing no sign of slowing down.

Investors can auto-trade the E-Mini Swing Trading strategy and many other strategies in their own account – see the Leaderboard for more details.

Perf1Monthly returns

A Tactical Equity Strategy

We have created a long-only equity strategy that aims to beat the S&P 500 total return benchmark by using tactical allocation algorithms to invest in equity ETFs.   One of the principal goals of the strategy is to protect investors’ capital during periods of severe market stress such as in the downturns of 2000 and 2008.  The strategy times the allocation of capital to equity ETFs or short-duration Treasury securities when investment opportunities are limited.

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Systematic Strategies is a hedge fund rather than an RIA, so we have no plans to offer the product to the public.  However, we are currently holding exploratory discussions with Registered Investment Advisors about how the strategy might be made available to their clients.

For more background, see this post on Seeking Alpha: http://tiny.cc/ba3kny

 

 

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Slide2

Tactical Mutual Fund Strategies

A recent blog post of mine was posted on Seeking Alpha (see summary below if you missed it).

Capital

The essence of the idea is simply that one can design long-only, tactical market timing strategies that perform robustly during market downturns, or which may even be positively correlated with volatility.  I used the example of a LOMT (“Long-Only Market-Timing”) strategy that switches between the SPY ETF and 91-Day T-Bills, depending on the current outlook for the market as characterized by machine learning algorithms.  As I indicated in the article, the LOMT handily outperforms the buy-and-hold strategy over the period from 1994 -2017 by several hundred basis points:

Fig6

 

Of particular note is the robustness of the LOMT strategy performance during the market crashes in 2000/01 and 2008, as well as the correction in 2015:

 

Fig7

 

The Pros and Cons of Market Timing (aka “Tactical”) Strategies

One of the popular choices the investor concerned about downsize risk is to use put options (or put spreads) to hedge some of the market exposure.  The problem, of course, is that the cost of the hedge acts as a drag on performance, which may be reduced by several hundred basis points annually, depending on market volatility.    Trying to decide when to use option insurance and when to maintain full market exposure is just another variation on the market timing problem.

The point of tactical strategies is that, unlike an option hedge, they will continue to produce positive returns – albeit at a lower rate than the market portfolio – during periods when markets are benign, while at the same time offering much superior returns during market declines, or crashes.   If the investor is concerned about the lower rate of return he is likely to achieve during normal years, the answer is to make use of leverage.

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Market timing strategies like Hull Tactical or the LOMT have higher risk-adjusted rates of return (Sharpe Ratios) than the market portfolio.  So the investor can make use of margin money to scale up his investment to about the same level of risk as the market index.  In doing so he will expect to earn a much higher rate of return than the market.

This is easy to do with products like LOMT or Hull Tactical, because they make use of marginable securities such as ETFs.   As I point out in the sections following, one of the shortcomings of applying the market timing approach to mutual funds, however, is that they are not marginable (not initially, at least), so the possibilities for using leverage are severely restricted.

Market Timing with Mutual Funds

An interesting suggestion from one Seeking Alpha reader was to apply the LOMT approach to the Vanguard 500 Index Investor fund (VFINX), which has a rather longer history than the SPY ETF.  Unfortunately, I only have ready access to data from 1994, but nonetheless applied the LOMT model over that time period.  This is an interesting challenge, since none of the VFINX data was used in the actual construction of the LOMT model.  The fact that the VFINX series is highly correlated with SPY is not the issue – it is typically the case that strategies developed for one asset will fail when applied to a second, correlated asset.  So, while it is perhaps hard to argue that the entire VFIX is out-of-sample, the performance of the strategy when applied to that series will serve to confirm (or otherwise) the robustness and general applicability of the algorithm.

The results turn out as follows:

 

Fig21

 

Fig22

 

Fig23

 

The performance of the LOMT strategy implemented for VFINX handily outperforms the buy-and-hold portfolios in the SPY ETF and VFINX mutual fund, both in terms of return (CAGR) and well as risk, since strategy volatility is less than half that of buy-and-hold.  Consequently the risk adjusted return (Sharpe Ratio) is around 3x higher.

That said, the VFINX variation of LOMT is distinctly inferior to the original version implemented in the SPY ETF, for which the trading algorithm was originally designed.   Of particular significance in this context is that the SPY version of the LOMT strategy produces substantial gains during the market crash of 2008, whereas the VFINX version of the market timing strategy results in a small loss for that year.  More generally, the SPY-LOMT strategy has a higher Sortino Ratio than the mutual fund timing strategy, a further indication of its superior ability to manage  downside risk.

Given that the objective is to design long-only strategies that perform well in market downturns, one need not pursue this particular example much further , since it is already clear that the LOMT strategy using SPY is superior in terms of risk and return characteristics to the mutual fund alternative.

Practical Limitations

There are other, practical issues with apply an algorithmic trading strategy a mutual fund product like VFINX. To begin with, the mutual fund prices series contains no open/high/low prices, or volume data, which are often used by trading algorithms.  Then there are the execution issues:  funds can only be purchased or sold at market prices, whereas many algorithmic trading systems use other order types to enter and exit positions (stop and limit orders being common alternatives). You can’t sell short and  there are restrictions on the frequency of trading of mutual funds and penalties for early redemption.  And sales loads are often substantial (3% to 5% is not uncommon), so investors have to find a broker that lists the selected funds as no-load for the strategy to make economic sense.  Finally, mutual funds are often treated by the broker as ineligible for margin for an initial period (30 days, typically), which prevents the investor from leveraging his investment in the way that he do can quite easily using ETFs.

For these reasons one typically does not expect a trading strategy formulated using a stock or ETF product to transfer easily to another asset class.  The fact that the SPY-LOMT strategy appears to work successfully on the VFINX mutual fund product  (on paper, at least) is highly unusual and speaks to the robustness of the methodology.  But one would be ill-advised to seek to implement the strategy in that way.  In almost all cases a better result will be produced by developing a strategy designed for the specific asset (class) one has in mind.

A Tactical Trading Strategy for the VFINX Mutual Fund

A better outcome can possibly be achieved by developing a market timing strategy designed specifically for the VFINX mutual fund.  This strategy uses only market orders to enter and exit positions and attempts to address the issue of frequent trading by applying a trading cost to simulate the fees that typically apply in such situations.  The results, net of imputed fees, for the period from 1994-2017 are summarized as follows:

 

Fig24

 

Fig18

Overall, the CAGR of the tactical strategy is around 88 basis points higher, per annum.  The risk-adjusted rate of return (Sharpe Ratio) is not as high as for the LOMT-SPY strategy, since the annual volatility is almost double.  But, as I have already pointed out, there are unanswered questions about the practicality of implementing the latter for the VFINX, given that it seeks to enter trades using limit orders, which do not exist in the mutual fund world.

The performance of the tactical-VFINX strategy relative to the VFINX fund falls into three distinct periods: under-performance in the period from 1994-2002, about equal performance in the period 2003-2008, and superior relative performance in the period from 2008-2017.

Only the data from 1/19934 to 3/2008 were used in the construction of the model.  Data in the period from 3/2008 to 11/2012 were used for testing, while the results for 12/2012 to 8/2017 are entirely out-of-sample. In other words, the great majority of the period of superior performance for the tactical strategy was out-of-sample.  The chief reason for the improved performance of the tactical-VFINX strategy is the lower drawdown suffered during the financial crisis of 2008, compared to the benchmark VFINX fund.  Using market-timing algorithms, the tactical strategy was able identify the downturn as it occurred and exit the market.  This is quite impressive since, as perviously indicated, none of the data from that 2008 financial crisis was used in the construction of the model.

In his Seeking Alpha article “Alpha-Winning Stars of the Bull Market“, Brad Zigler identifies the handful of funds that have outperformed the VFINX benchmark since 2009, generating positive alpha:

Fig20

 

What is notable is that the annual alpha of the tactical-VINFX strategy, at 1.69%, is higher than any of those identified by Zigler as being “exceptional”. Furthermore, the annual R-squared of the tactical strategy is higher than four of the seven funds on Zigler’s All-Star list.   Based on Zigler’s performance metrics, the tactical VFINX strategy would be one of the top performing active funds.

But there is another element missing from the assessment. In the analysis so far we have assumed that in periods when the tactical strategy disinvests from the VFINX fund the proceeds are simply held in cash, at zero interest.  In practice, of course, we would invest any proceeds in risk-free assets such as Treasury Bills.   This would further boost the performance of the strategy, by several tens of basis points per annum, without any increase in volatility.  In other words, the annual CAGR and annual Alpha, are likely to be greater than indicated here.

Robustness Testing

One of the concerns with any backtest – even one with a lengthy out-of-sample period, as here – is that one is evaluating only a single sample path from the price process.  Different evolutions could have produced radically different outcomes in the past, or in future. To assess the robustness of the strategy we apply Monte Carlo simulation techniques to generate a large number of different sample paths for the price process and evaluate the performance of the strategy in each scenario.

Three different types of random variation are factored into this assessment:

  1. We allow the observed prices to fluctuate by +/- 30% with a probability of about 1/3 (so, roughly, every three days the fund price will be adjusted up or down by that up to that percentage).
  2. Strategy parameters are permitted to fluctuate by the same amount and with the same probability.  This ensures that we haven’t over-optimized the strategy with the selected parameters.
  3. Finally, we randomize the start date of the strategy by up to a year.  This reduces the risk of basing the assessment on the outcome from encountering a lucky (or unlucky) period, during which the market may be in a strong trend, for example.

In the chart below we illustrate the outcome from around 1,000 such randomized sample paths, from which it can be seen that the strategy performance is robust and consistent.

Fig 19

 

Limitations to the Testing Procedure

We have identified one way in which this assessment understates the performance of the tactical-VFINX strategy:  by failing to take into account the uplift in returns from investing in interest-bearing Treasury securities, rather than cash, at times when the strategy is out of the market.  So it is only reasonable to point out other limitations to the test procedure that may paint a too-optimistic picture.

The key consideration here is the frequency of trading.  On average, the tactical-VFINX strategy trades around twice a month, which is more than normally permitted for mutual funds.  Certainly, we have factored in additional trading costs to account for early redemptions charges. But the question is whether or not the strategy would be permitted to trade at such frequency, even with the payment of additional fees.  If not, then the strategy would have to be re-tooled to work on long average holding periods, no doubt adversely affecting its performance.

Conclusion

The purpose of this analysis was to assess whether, in principle, it is possible to construct a market timing strategy that is capable of outperforming a VFINX fund benchmark.  The answer appears to be in the affirmative.  However, several practical issues remain to be addressed before such a strategy could be put into production successfully.  In general, mutual funds are not ideal vehicles for expressing trading strategies, including tactical market timing strategies.  There are latent inefficiencies in mutual fund markets – the restrictions on trading and penalties for early redemption, to name but two – that create difficulties for active approaches to investing in such products – ETFs are much superior in this regard.  Nonetheless, this study suggest that, in principle, tactical approaches to mutual fund investing may deliver worthwhile benefits to investors, despite the practical challenges.

Capitalizing on the Coming Market Crash

Long-Only Equity Investors

Recently I have been discussing possible areas of collaboration with an RIA contact on LinkedIn, who also happens to be very familiar with the hedge fund world.  He outlined the case of a high net worth investor in equities (long only), who wanted to remain invested, but was becoming increasingly concerned about the prospects for a significant market downturn, or even a market crash, similar to those of 2000 or 2008.

I am guessing he is not alone: hardly a day goes by without the publication of yet another article sounding a warning about stretched equity valuations and the dangerously elevated level of the market.

The question put to me was, what could be done to reduce the risk in the investor’s portfolio?

Typically, conservative investors would have simply moved more of their investment portfolio into fixed income securities, but with yields at such low levels this is hardly an attractive option today. Besides, many see the bond market as representing an even more extreme bubble than equities currently.

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Hedging Strategies

The problem with traditional hedging mechanisms such as put options, for example, is that they are relatively expensive and can easily reduce annual returns from the overall portfolio by several hundred basis points.  Even at current low level of volatility the performance drag is noticeable, since the potential upside in the equity portfolio is also lower than it has been for some time.  A further consideration is that many investors are not mandated – or are simply reluctant – to move beyond traditional equity investing into complex ETF products or derivatives.

An equity long/short hedge fund product is one possible solution, but many equity investors are reluctant to consider shorting stocks under any circumstances, even for hedging purposes. And while a short hedge may provide some downside protection it is unlikely to fully safeguard the investor in a crash scenario.  Furthermore, the cost of a hedge fund investment is typically greater than for a long-only product, entailing the payment of a performance fee in addition to management fees that are often higher than for standard investment products.

The Ideal Investment Strategy

Given this background, we can say that the ideal investment strategy is one that:

  • Invests long-only in equities
  • Is inexpensive to implement (reasonable management fees; no performance fees)
  • Does not require shorting stocks, or expensive hedging mechanisms such as options
  • Makes acceptable returns during both bull and bear markets
  • Is likely to produce positive returns in a market crash scenario

A typical buy-and-hold approach is unlikely to meet only the first three requirements, although an argument could be made that a judicious choice of defensive stocks might enable the investment portfolio to generate returns at an “acceptable” level during a downturn (without being prescriptive as to the precise meaning of that term may be).  But no buy-and-hold strategy could ever be expected to prosper during times of severe market stress.  A more sophisticated approach is required.

Market Timing

Market timing is regarded as a “holy grail” by some quantitative strategists.  The idea, simply, is to increase or reduce risk exposure according to the prospects for the overall market.  For a very long time the concept has been dismissed as impossible, by definition, given that markets are mostly efficient.  But analysts have persisted in the attempt to develop market timing techniques, motivated by the enormous benefits that a viable market timing strategy would bring.  And gradually, over time, evidence has accumulated that the market can be timed successfully and profitably.  The rate of progress has accelerated in the last decade by the considerable advances in computing power and the development of machine learning algorithms and application of artificial intelligence to investment finance.

I have written several articles on the subject of market timing that the reader might be interested to review (see below).  In this article, however, I want to focus firstly on the work on another investment strategist, Blair Hull.

http://jonathankinlay.com/2014/07/how-to-bulletproof-your-portfolio/

 

http://jonathankinlay.com/2014/07/enhancing-mutual-fund-returns-with-market-timing/

The Hull Tactical Fund

Blair Hull rose to prominence in the 1980’s and 1990’s as the founder of the highly successful quantitative option market making firm, the Hull Trading Company which at one time moved nearly a quarter of the entire daily market volume on some markets, and executed over 7% of the index options traded in the US. The firm was sold to Goldman Sachs at the peak of the equity market in 1999, for a staggering $531 million.

Blair used the capital to establish the Hull family office, Hull Investments, and in 2013 founded an RIA, Hull Tactical Asset Allocation LLC.   The firm’s investment thesis is firmly grounded in the theory of market timing, as described in the paper “A Practitioner’s Defense of Return Predictability”,  authored by Blair Hull and Xiao Qiao, in which the issues and opportunities of market timing and return predictability are explored.

In 2015 the firm launched The Hull Tactical Fund (NYSE Arca: HTUS), an actively managed ETF that uses quantitative trading model to take long and short positions in ETFs that seek to track the performance of the S&P 500, as well as leveraged ETFs or inverse ETFs that seek to deliver multiples, or the inverse, of the performance of the S&P 500.  The goal to achieve long-term growth from investments in the U.S. equity and Treasury markets, independent of market direction.

How well has the Hull Tactical strategy performed? Since the fund takes the form of an ETF its performance is a matter in the public domain and is published on the firm’s web site.  I reproduce the results here, which compare the performance of the HTUS ETF relative to the SPDR S&P 500 ETF (NYSE Arca: SPY):

 

Hull1

 

Hull3

 

Although the HTUS ETF has underperformed the benchmark SPY ETF since launching in 2015, it has produced a higher rate of return on a risk-adjusted basis, with a Sharpe ratio of 1.17 vs only 0.77 for SPY, as well as a lower drawdown (-3.94% vs. -13.01%).  This means that for the same “risk budget” as required to buy and hold SPY, (i.e. an annual volatility of 13.23%), the investor could have achieved a total return of around 36% by using margin funds to leverage his investment in HTUS by a factor of 2.8x.

How does the Hull Tactical team achieve these results?  While the detailed specifics are proprietary, we know from the background description that market timing (and machine learning concepts) are central to the strategy and this is confirmed by the dynamic level of the fund’s equity exposure over time:


Hull2

 

A Long-Only, Crash-Resistant Equity Strategy

A couple of years ago I and my colleagues carried out an investigation of long-only equity strategies as part of a research project.  Our primary focus was on index replication, but in the course of our research we came up with a methodology for developing long-only strategies that are highly crash-resistant.

The performance of our Long-Only Market Timing strategy is summarized below and compared with the performance of the HTUS ETF and benchmark SPY ETF (all results are net of fees).  Over the period from inception of the HTUS ETF, our LOMT strategy produced a higher total return than HTUS (22.43% vs. 13.17%), higher CAGR (10.07% vs. 6.04%), higher risk adjusted returns (Sharpe Ratio 1.34 vs 1.21) and larger annual alpha (6.20% vs 4.25%).  In broad terms, over this period the LOMT strategy produced approximately the same overall return as the benchmark SPY ETF, but with a little over half the annual volatility.

 

Fig4

 

Fig5

Application of Artificial Intelligence to Market Timing

Like the HTUS ETF, our LOMT strategy operates with very low fees, comparable to an ETF product rather than a hedge fund (1% management fee, no performance fees).  Again, like the HTUS ETF our LOMT products makes no use of leverage.  However, unlike HTUS it avoids complicated (and expensive) inverse or leveraged ETF products and instead invests only in two assets – the SPY ETF and 91-day US Treasury Bills.  In other words, the LOMT strategy is a pure market timing strategy, moving capital between the SPY ETF and Treasury Bills depending on its forecast of future market performance.  These forecasts are derived from machine learning algorithms that are specifically tuned to minimize the downside risk in the investment portfolio.  This not only makes strategy returns less volatile, but also ensures that the strategy is very robust to market downturns.

In fact, even better than that,  not only does the LOMT strategy tend to avoid large losses during periods of market stress, it is capable of capitalizing on the opportunities that more volatile market conditions offer.  Looking at the compounded returns (net of fees) over the period from 1994 (the inception of the SPY ETF) we see that the LOMT strategy produces almost double the total profit of the SPY ETF, despite several years in which it underperforms the benchmark.  The reason is clear from the charts:  during the periods 2000-2002 and again in 2008, when the market crashed and returns in the SPY ETF were substantially negative, the LOMT strategy managed to produce positive returns.  In fact, the banking crisis of 2008 provided an exceptional opportunity for the LOMT strategy, which in that year managed to produce a return nearing +40% at a time when the SPY ETF fell by almost the same amount!

 

Fig6

 

Fig7

 

Long Volatility Strategies

I recall having a conversation with Nassim Taleb, of Black Swan fame, about his Empirica fund around the time of its launch in the early 2000’s.  He explained that his analysis had shown that volatility was often underpriced due to an under-estimation of tail risk, which the fund would seek to exploit by purchasing cheap out-of-the-money options.  My response was that this struck me a great idea for an insurance product, but not a hedge fund – his investors, I explained, were going to hate seeing month after month of negative returns and would flee the fund.  By the time the big event occurred there wouldn’t be sufficient AUM remaining to make up the shortfall.  And so it proved.

A similar problem arises from most long-volatility strategies, whether constructed using options, futures or volatility ETFs:  the combination of premium decay and/or negative carry typically produces continuing losses that are very difficult for the investor to endure.

Conclusion

What investors have been seeking is a strategy that can yield positive returns during normal market conditions while at the same time offering protection against the kind of market gyrations that typically decimate several years of returns from investment portfolios, such as we saw after the market crashes in 2000 and 2008.  With the new breed of long-only strategies now being developed using machine learning algorithms, it appears that investors finally have an opportunity to get what they always wanted, at a reasonable price.

And just in time, if the prognostications of the doom-mongers turn out to be correct.

Contact Hull Tactical

Contact Systematic Strategies