Deciphering Correlation Hedged Momentum

In a new SeekingAlpha contribution we combine PAA’s protective multi-market breadth approach with a generalized momentum metric based on correlation hedged returns. The resulting model is called Generalized Protective Momentum (GPM). In this blogpost the correlation hedge is deciphered.


The correlation hedge is a simplified version of Keller and Butler’s EAA-formula (see paper or primer). For GPM we only use return and correlation information as momentum metric. We do so with two variations:
  • GPMxM: the correlation multiplied return metric ri * ( 1 – ci )
  • GPMxF: the correlation fractioned return metric ri / ( 1 + ci )
where x is the degree of crash protection, ri is the average return of asset i over 1, 3, 6 and 12 months, and ci the 12-month correlation of asset i with the equal weighted “risky” investment universe. The correlation multiplier ( 1 – ci ) is based on the EAA-model, the correlation fraction 1 / ( 1 + ci ) was recently suggested by Wouter Keller. For the mechanics of the crash protection algorithm, see the PAA-post.

In the graph below, the two correlation hedge variations are painted.


Introducing Protective Asset Allocation

Protective Asset Allocation (PAA) is a new provident long only tactical investment strategy that combines a dual momentum approach with a vigorous capital preservation routine. The key elements of PAA are:
  • dual momentum based timing and selection mechanism
  • innovative c(r)ash protection routine through protective momentum
  • support for separate “risk-on” and “risk-off" universes
Each of these building blocks will be explained quite comprehensively followed by a detailed comparative backtest covering 45 years (Dec. 1970 – Dec. 2015). But first be ready for a truckload of conceptual particularities ;-)


In our quest for a yield neutral absolute return performance strategy Wouter Keller and I developed PAA (long only) with its innovative protective momentum approach for capital preservation in times of market turmoil. The interested reader might consider reading our PAA-paper on SSRN too.

PAA exploits the well-defined momentum phenomenon: the empirically observed tendency for asset prices to keep moving in the same direction. By applying PAA to a broad diversified global universe of sufficiently uncorrelated ETFs, PAA will auto-detect bull trends that emerge. Meanwhile protective momentum keeps guard over global market-breadth to adjust the “equity” : “cash” spread of the portfolio. And when trends shift, PAA catches the change and adapts, be it bullish or bearish. In doing so PAA is purely mechanical, so there is no need second guessing market conditions nor predicting trends. PAA is capable of delivering absolute return performance with 1-year-rolling-return win rates of more than 95% (R1yWin>0%) and 99% (R1yWin>-5%).

Equity chart of the PAA strategy demonstrating high return/risk performance

Portfolio Level Monte Carlo Analysis

Following up on the prior Strategy Stress Testing post: with the release of AmiBroker version 6.10.0 a new Monte Carlo mode has come available for simulating portfolio equity changes. Instead of randomizing the trade list, the new mode uses bar-per-bar percent equity changes at the portfolio level to generate permutations. Consequently cross-sectional correlations are preserved. According to AmiBroker’s developer, the new method is perfectly fine for multiple overlapped positions, provided the number of bar-per-bar equity changes is sufficiently large (> 100).


The portfolio level Monte Carlo simulation is controlled by a couple of new SetOption fields which allow for AFL implementation right into the strategy code:
The Monte Carlo Portfolio Analysis code is suitable for copy/paste inside a rotational model like the familair Simple GMR code attached to the prior Monte Carlo post. However, my preferred method is to save the code as a separate file for inclusion in strategy models by calling the #include command:

Lab Announcement


After spending ages on research a couple of exciting new developments will be published shorty:
  • Portfolio level Monte Carlo analysis
  • DIY global multi asset universe with 21 ETF-proxies covering a history of 45+ years
  • “One-Click” export from Excel to multiple csv (in R)
  • Enhanced c(r)ash protection routine for tactical investment strategies
  • Dual universe support for differentiation of risk-on and risk-off assets
  • Surveying volatility driven dynamic lookback indicators

Strategy Stress Testing à la Monaco

After a short, admittedly rather superfluous, historical digression, this post will introduce Monte Carlo Analysis. What is Monte Carlo Analysis? Why is such analysis useful if not prerequisite for a strategy trader? What does it supplement to customary backtest information? By exploring the darker corners of a strategy the objective of this post is revealing real risk.

Crunching numbers in a monastery

During the first half of the 1600s a French monk, Marin Mersenne, had many acquaintances in the scientific world. Mersenne studied (and taught) theology, philosophy, mathematics and music. He communicated extensively with other scholars like Descartes, Pascal, Huygens and Galilei.

In spite of being a theologian and philosopher primarily, Mersenne’s name is associated with prime numbers that compound to Mn = 2n – 1. Such numbers are called Mersenne primes. The first four Mersenne primes are 3, 7, 31 and 127 and significantly a Mersenne prime (219937−1) is elementary for the most commonly used version of the Mersenne Twister.

The Mersenne Twister is a fast generator of high-quality pseudorandom integers. Recently AmiBroker’s already extensive feature set was expanded with a Mersenne Twister based Monte Carlo simulator which is capable of rendering 30+ million trades per second (!). More specific, the Monte Carlo simulator runs series of trade sequences based on backtest output and uses the high-quality Mersenne Twister for randomizing the order of the trades.

And so we finally arrive down the stairs of the famous "Casino de Monte-Carlo" in mondain Monaco ;-)


Why stress test strategies with Monte Carlo Analysis?

Before we start familiarizing ourselves with Monte Carlo Analysis let’s first pick a sample strategy for illustration purposes: SeekingAlpha's contributor Varan's Simple GMR. Each month all available trading capital is re-allocated to the top performing ETF out of a basket with IJJ, EFA, IEV, EPP, QQQ, EEM and TLT. See Varan's post for details. For establishing points of reference and collecting the trade data required for a Monte Carlo Analysis, a backtest is run starting at year-end 2003 and ending August 2015 using high-quality monthly total return data as provided by Norgate Premium Data (Alpha-tester program).

The equity curve as well as the distribution of the yearly returns obtained from the backtest look reasonable, even considering the 2008 drawdown when compared to the market in general. Volatility is not too high. Actually, the ratios for Sharpe, Sortino and Calmar are quite nice. The complete chart suite is available in the Google drive folder connected to this post (zooming required!).

Portfolio performance over 2004 - 2015