Wes Gray, who studied with Eugene Fama, runs a firm called Alpha Architect. In his most recent weekly newsletter, he mentioned a new academic paper that asks the question: Do Stocks Outperform Treasury Bills?

Here is the abstract summary of the paper and the link to SSRN's publication of the full paper:

Hendrik Bessembinder Fifty eight percent of CRSP common stocks have lifetime holding period returns less than those on one-month Treasuries. The modal lifetime return is -100%. When stated in terms of lifetime dollar wealth creation, the entire net gain in the U.S. stock market since 1926 is attributable to the best-performing four percent of listed stocks, as the other ninety six percent collectively matched one-month Treasury bills. These results highlight the important role of positive skewness in the cross-sectional distribution of stock returns. The skewness arises both because monthly returns are positively skewed and because compounding returns induces skewness. The results help to explain why active strategies, which tend to be poorly diversified, most often underperform.

John Netto writes:

I was fortunate enough to have Wes, a former Marine Corps Officer and Iraq war veteran, write the foreword to my book. He's an inspiration. 

Larry Williams writes:

I thought this was common knowledge. Goldman did a studies years ago with the same conclusion and as I recall so did Edgar Lawrence Smith in the 1930s.

Ralph Vince writes:

Just go look at what happens to stocks when earnings yield and/or dividend yields exceed a certain multiple on t bill returns.

I have grown generally very skeptical of anything that emanates from U of Chicago. There is a philosophical problem there I have discovered, incongruent with real-world markets, but that is a subject for a different, future thread possibly.

And fwiw, these multiples of t bill returns, as metrics of valuation, are quite opposed here to the seemingly pervasive meme of being at or in a bear market's doorstep.

Stefan Jovanovich writes: 

Like Pat McAfee, I am now (and have been for a while) a fan of players, not teams. (The baseball Giants remain an exception because the old franchise at the Polo Grounds was my childhood home. Even the Mobile Shippers (the Negro team in Mobile, Alabama that nurtured Henry Aaron and Willie McCovey) never quite made me a die-hard.) So, I can offer no opinions about the University of Chicago or any other academic team. I am a fan of Eugene Fama because he seems to have been remarkably generous to his graduate students in encouraging them and their work, even when he thought they were "wrong". I also admire him for being the only person I know of who has questioned the utility of the United States having a central bank when the dollar, as currency, has no independent monetary existence.

As LW notes, Edgar Lawrence Smith put the case that, over any two decade period that he studied, "a diversification of common stocks has …, in the end, shown better results, both as to income return and safety of principal, than a similar investment in bonds." Professor Bessembinder's paper does not contradict that conclusion. His argument is that most stocks do no better than Treasury bills; the out-performance of "the market" is dependent on a very few spectacular winners. I thought this actually reinforced the belief of the List members that the Jack Bogle's advice - "Buy Everything and Keep It Forever" - was all wet.

Ralph Vince writes: 

As an aside but related data point on this discussion, as of Friday's close, the geometric multiple on the 30 year constant is at 35. It has NEVER been this high above the S&P P/E Multiple.

I want to drink in the bigger picture.

Kim Zussman writes: 

The only free lunch is diversification (including temporally, which means B&H).

Ralph Vince writes: 

It is the ILLUSION of a free lunch. 

Diversification works over long periods of time for the average investor because it creates a slight return asymmetry that compounds over time.

True. However, asymptotically, it is gone with the wind.

By way of a simplistic analogy. Consider the single proposition of a coin toss, heads you double, tails you lose all. So you diversify among 4 coin where the pairwise correlation between any two is r=0 (much better than you can find in capital markets, esp under conditions of extreme moves). Let's say you decide to play 4 coins simultaneously. So rather than a .5 probability of losing it all, you have a .0625 probability.

Eventually, everyone gets pasted. for whatever they have exposed to risk.

It is how you handle that - that inevitable lightning strike if you stick around long enough (and as I always say, if you live long enough, you'll get to experience everything - twice! if you live long enough). That is the only thing that ultimately matters in this primal arena. All other "edges," and supposed free lunches are only temporal.

Jonathan Bower writes: 

Ralph, you will be able to out math me so take all of this with a grain of salt. Maybe I can set up a simulation at some point that will prove my point…

But I think your assumptions may be not realistic for the case at hand, the average investor not skilled traders. While the 0 correlation gives an edge to your example because as you rightly point out that's not the case for capital markets. N of 4 is also not sufficiently diversified. However the double or 0 is possibly a far more restrictive constraint. In reality owning a basket of stocks the outcomes are more like 0 and 10x +. And while it is possible to go bust, going to 0 (without leverage) is actually an unlikely outcome as the stock will be sold before it gets to that point in most cases. The difference is you can (theoretically) come back from a 99% loss, not 100%.

I'm going to stand by my original comment and say that diversification creates return asymmetry which leads to long run higher compound returns than something less diversified.

Ralph Vince replies:


I don't claim to be a mathematician, so to explain this sans math for both of our sakes……

The problem is that is that

For any portfolio, regardless of the number of components or the outcome parameters of those components sees a probability of drawdown of any specified magnitude approaches 1 as the number of holding periods gets ever-greater.

So yes, you can amend the parameters of outcomes, and you can increase the number of components (and clearly, doing so mitigates the effect on the portfolio from a disaster of any individual component, but the tenet above still holds, only the expected time until you can expect to see it grows longer. I would point out though, that we are dealing with components of perverse distribution and correlations among themselves that conspire against us when things go wrong; the time expected until we can expect disaster is much shorter than anyone realizes going in. Random events, even coin tosses of "double or nothing," are far more gentle and forgiving than the real world tends to bear out with regards to capital markets.

And none of this takes into account the effects of leverage, which is ubiquitous, and unavoidable — and misunderstood in that there is always leverage present.It may not be borrowing, but how much we do not borrow is also a matter of "leverage." To mt point in this regard, and again referring to the simple proposition of coin tosses, imagine the coin toss that pays 2:1. If we have a portfolio of one component, if we risk more than .5 of our stake, per play, we go broke with certainty as the number of compounding periods grows ever greater. Growth here is maximized at risking 25%.

If we have three coins paying 2:1 whose correlation between them is 0, we maximize our compound growth by wagering .21 on each coin, each component. However, if the correlations slip to +1, it is the same shape in leverage space as the individual component whose peak is at .25 (aggregate wagered among the three coins) not .63 (.21 x 3) which has us beyond the .5 point in the individual component portfolio, and insures are re going broke as we accumulate compounding periods.

It is quite insidious, and far more prone to danger than Markowitz ever envisioned I believe.

In fact, when one takes leverage into account, the surface of "leverage space" as I refer to it, presents potential danger from a single component (no matter how many components comprise the portfolio) that can wipe out the investor. In the following graph, figure 3 from the paper here you an see how, at a steep enough "leverage" (and these leverages are < 1) on any individual component (2 in this case, to demonstrate leverage space in 3 dimensions) any point along either of the two horizontal axes where the corresponding vertical axis is <1 is assured ruin as compounding periods accumulate (anything multiplied repeatedly by a number n, 0 >= n < 1 approaches zero with each successive multiplication).

Diversification tends to reduce period-on-period variance. Variance is not risk, but a diminution in returns.





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