The Art of Streetplay

Tuesday, October 11, 2005

Rydex Preaches "Essential Portfolio Theory"

Rydex Introduces "Essential Portfolio Theory"

General
Fancy name but essentially what they're trying to preach is diversification across asset classes-- not only stocks and bonds but also real estate, commodities, and much more. In doing so, they intend to provide value through diversification, hopefully moving up that efficient frontier through the use of relatively less correlated assets. Additionally, though, one must ask the question-- would individual investors even know what the efficient composition should be of these asset classes, even if one knows that diversification is a good thing? Probably not. Rydex can spend some bucks on a few geniuses and then spread the overhead over the hopefully large number of people who end up buying into the ETF's. Obviously this is something an individual investor could only do through concerted effort and much more resources expended.

Rydex's claim is that a strategy like this one used to only be available to institutional investors, but Rydex intends to bring them to individual investors. This makes sense. I wonder just how much turnover there is relative to some of the more traditional indexation strategies, but my guess is that it isn't bad.

People Involved
Princeton professor John Mulvey is helping Rydex in the construction of EPT-based portfolios. Given the information provided about his consulting background, and his expertise in large-scale optimization models, it seems pretty clear that he is doing some linear or non-linear programming for portfolio optimization purposes. For those who are unfamiliar with how these programs work I'll attempt to shine some light on the subject.

Linear and non-linear programs maximize something called an objective function subject to a set of constraints. For example assume that you are an institutional money manager and cannot put more than 1% of your wealth in any individual stock, no more than 10% of your wealth in any particular sector, cannot go short, can only invest in equities in the US and in China, and know that your investor base is primarily looking for a slow and steady return with little volatility. One could structure a linear program to create an efficient or optimal portfolio, given some past price (and perhaps volume) data on the instruments you are allowed to invest in. Rebalancing could be done every so often by re-running the program which is trained on perhaps some sort of a rolling time horizon and/or forgetting time (both of which can also be tweaked, although one must watch out for non-stationarity and overfitting as usual). The optimal program would probably be something along the following:

Minimize the volatility of your portfolio holdings {X(1),X(2),X(3),...X(N)}, where X(1...N) comprise the weightings of each stock which can be in your portfolio, subject to the constraint that
(1) your expected annual return is R(target),
(2) {X(1),X(2),X(3),...X(N)} must all be less than or equal to .01,
(3) {S(1),S(2),(3),...S(n)}, your corresponding sector weightings, must all be less than or equal to .1,
(4){X(1),X(2),X(3),...X(N)} must all be greater than or equal to 0 to avoid going short,
...
etc etc. 1...N encapsulates the constraint on the universe of potential holdings, and R(target) is probably a spread off of the risk free rate.

Turning to an EPT portfolio, then, one will probably see something similar to this. Perhaps they are trying to maximize returns subject to a minimum level of volatility. Their investment universe 1...N is most certainly quite large to account for the broad number of asset classes being drawn upon. Their rebalancing time is probably pretty big so as to keep turnover low. Finally it is only reasonable to assume that they are factoring in the differential transaction costs between these different asset classes, because it is most certainly more expensive to trade, say, a corporate bond in a local Brazilian paper company than it is to buy up a handful of shares of IBM.

Finally, given the fact that I assume these EPT portfolios are going to be around for a while, I would assume that the portfolios would be conditioned to be multi-period optimal as well through the use of simulation or a variant of the Kelly criterion or something like that.

Last Bits of News on This and Bigger Picture Perspective
Not much else to say. Mulvey and Reilly, the Director of Fund Research at Rydex, spoke in Manchester on June 27th and June 28th regarding EPT as part of a very large conference which included the likes of Colin Powell. So the word has been out for a few months already.

Overall it seems that the ETF world is moving in the direction WSDT is moving in. These Rydex ETF's and some of the promotional material they've been spitting out smack of a more active, more broadly diversified, generally more innovative breed of ETF's. Like I've said before, conditional on WSDT releasing something of value with little overlap to these other more innovative ETF's, this sort of movement is indeed quite good. When Rydex goes over the news wire saying that Modern Portfolio Theory could use some help given the competitive nature of today's market environment, and that more needs to be done by the individual investor should the individual investor want to meet his or her investing goals over the longer term, Rydex is basically saying (IMHO) "I will pony up a lot of money to educate these stupid people who just don't understand that they are investing sub-optimally on a risk adjusted basis and could use the helping hand of firms like ours and WSDT who provide lower cost, more efficient investment products."

That being said, still left wondering what WSDT is going to do.
-Dan

ps. Funny to note-- so on the one hand you have WSDT which is heavily based out of Wharton, whose head of fund research is a Wharton professor. On the other hand you have Rydex which is coming out with innovative indices and is drawing on the brainpower of a Princeton professor. It seems we cannot escape this rivalry between Princeton and Wharton (go Wharton!).

1 Comments:

  • You have a very interesting view on stock analysis. I would love to hear your professional opinion about the following article I came across, please sent your comments to angle_8866@yahoo.com.cn:

    3 Steps To Profitable Stock Picking

    Stock picking is a very complicated process and investors have different approaches. However, it is wise to follow general steps to minimize the risk of the investments. This article will outline these basic steps for picking high performance stocks.

    Step 1. Decide on the time frame and the general strategy of the investment. This step is very important because it will dictate the type of stocks you buy.

    Suppose you decide to be a long term investor, you would want to find stocks that have sustainable competitive advantages along with stable growth. The key for finding these stocks is by looking at the historical performance of each stock over the past decades and do a simple business S.W.O.T. (Strength-weakness-opportunity-threat) analysis on the company.

    If you decide to be a short term investor, you would like to adhere to one of the following strategies:

    a. Momentum Trading. This strategy is to look for stocks that increase in both price and volume over the recent past. Most technical analyses support this trading strategy. My advice on this strategy is to look for stocks that have demonstrated stable and smooth rises in their prices. The idea is that when the stocks are not volatile, you can simply ride the up-trend until the trend breaks.

    b. Contrarian Strategy. This strategy is to look for over-reactions in the stock market. Researches show that stock market is not always efficient, which means prices do not always accurately represent the values of the stocks. When a company announces a bad news, people panic and price often drops below the stock's fair value. To decide whether a stock over-reacted to a news, you should look at the possibility of recovery from the impact of the bad news. For example, if the stock drops 20% after the company loses a legal case that has no permanent damage to the business's brand and product, you can be confident that the market over-reacted. My advice on this strategy is to find a list of stocks that have recent drops in prices, analyze the potential for a reversal (through candlestick analysis). If the stocks demonstrate candlestick reversal patterns, I will go through the recent news to analyze the causes of the recent price drops to determine the existence of over-sold opportunities.

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    Step 3. Once you have a list of stocks to buy, you would need to diversify them in a way that gives the greatest reward/risk ratio (The Sharpe Ratio). One way to do this is conduct a Markowitz analysis for your portfolio. The analysis is from the Modern Portfolio Theory and will give you the proportions of money you should allocate to each stock. This step is crucial because diversification is one of the free-lunches in the investment world.

    These three steps should get you started in your quest to consistently make money in the stock market. They will deepen your knowledge about the financial markets, and would provide a sense of confidence that helps you to make better trading decisions.

    About the Author: Zheng Fang is the creator of Advance Stock Pattern Scanner of www.cisiova.com and the owner of several stock picking blogs:

    1. Optimal Portfolio
    2. Candlestick Stock Picks
    3. Cup and Handle Stock Picks
    4. Technical Analysis

    By Blogger stockexpert, at 10:26 PM  

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