Investing

Finding Alpha

Posted by Peter on December 1, 2009
Posted in: Investing. Tagged: , .

Book review: Finding Alpha: The Search for Alpha When Risk and Return Break Down by Eric Falkenstein.

This book presents mostly convincing arguments that refute the basic principle of CAPM that riskier investments are rewarded with higher returns, and the relation between risk and returns is better explained by modeling investors as wanting high returns relative to other investors rather than high absolute returns. But the quality of the arguments is quite variable. Much of the book assumes a good understanding of finance theory. If you don’t understand the importance of a Sharpe ratio, you’re not in his target audience.

I was not convinced by his most heavily emphasized empirical claim, that returns on equities are unrelated to beta because controlling for size eliminates the apparent relation. There’s enough connection between size and risk that this raises many questions he doesn’t answer (e.g. JB Berk, A critique of size-related anomalies). But later on he devotes a chapter to a wide variety of evidence that overcomes these concerns, and somewhat supports his claim that for riskier investments, the correlation between risk and return is negative (for the safest investments, it’s positive). And the authoritative Fama and French paper has more convincing evidence about beta – even without controlling for size, the correlation between beta and returns vanished during the 1963 to 1990 period.

He claims that the equity risk premium is effectively zero for a typical investor. His attempt to add up the different adjustments is confusing. He concludes with a table showing size adjustments to that standard estimate that add up to a mind-boggling 15 percent, which would result in a “premium” of -9 percent or so. But adding them is clearly wrong – the tax adjustment assumes the absence of some of the other adjustments. Still, the arguments he assembles from other researchers imply a good chance that the sign of the equity risk premium varies with the time period over which it’s measured.

He suggests some strategies to invest more wisely as a result of the ideas he presents, which he aptly summarizes as “selling hope relative to the market” (i.e. treating volatile stocks as overpriced due to a hope premium). But claiming this produces “superior returns, with less risk however measured” is too strong. Financial risk is not the only relevant measure of risk. Following his advice has social risks that he hints at elsewhere. Being invested in boring stocks in a bubble impairs your ability to engage in some interesting conversations, and you won’t make up for that by mentioning how you outperform the market in times when other want to avoid remembering their investments. Is it possible to minimize both kinds of risks by investing token amounts in ways that trendy folks are talking about, and investing most of your money to maximize your Sharpe ratio? Or does that require too much cognitive dissonance?

The book encourages pessimism, especially about the effects of people wanting relative wealth, and makes disturbing claims such as “Envy is necessary for compassion”.

He provides a number of other good ideas about investing, such as the possibility that the internet bubble adds a big anomaly to many data sets used for backtesting.

Confusing S&P Index Earnings Numbers

Posted by Peter on July 4, 2009
Posted in: Investing. Tagged: .

I just noticed some confused arguments between Jeremy Siegel and Standard and Poors over how to aggregate earnings for companies in a stock index to produce a meaningful report of what the companies in the index earned.
See here and here.

Siegel provides an example involving percent changes in Exxon-Mobil and Jones Apparel. But that has a weak resemblance to what S&P is doing. A more accurate analogy to what S&P is doing would use changes to market cap rather than percent changes. If Jones Apparel declined in market cap by $10 billion, it would hurt the index just as badly as a $10 billion decline in Exxon-Mobil’s market cap. Looked at that way, S&P’s approach looks sensible.

But since Jones Apparel has a market cap of less than $1 billion, the current bankruptcy laws make it far-fetched that Jones Apparel could lose more than $1 billion in market cap.

If you’re using earnings as a proxy for the health of the economy, S&P’s method doesn’t create a problem – the bankruptcy laws affect who loses money, but the money is still lost. But for an investor, Siegel has a point which is half right.

Siegel’s solution of weighting earnings by market cap may work well under any realistic conditions, but has no sensible theory behind it, and can fail badly under some far-fetched conditions. Imagine that Jones Apparel reports an unexpected one-time windfall of $1 trillion, which ought to raise the market cap of Jones Apparel by about $1 trillion. The way S&P computes S&P 500 earnings, an investor looking at S&P 500 earnings would see a strong hint that the value of the S&P 500 ought to rise by about $1 trillion. But under Siegel’s method, the initial effect on S&P 500 earnings would suggest a barely noticeable rise in the value of the S&P 500 of under $1 billion. Then at some point the Jones Apparel market cap would soar and the S&P 500 earnings would be recomputed with much different weights and investors would see a much different picture. So Siegel has proposed something which could result in a potentially large change in reported S&P 500 earnings without any change in the what shares someone who invests in the S&P 500 holds and without any changes in reported earnings.

Morningstar has a method (PDF) designed for evaluating portfolios that uses a harmonic weighted average and ignores companies with negative earnings. That has advantages, but the magnitude of losses provides some hints about how far a company is from profitability, so an ideal method should pay some attention to losses.

Siegel mentions comments by Shiller that suggest Shiller has better (but possibly impractical) ideas. I doubt Shiller’s analysis provides as much support for Siegel’s argument as Siegel claims.

Any sensible investor looks at a multi-year average of earnings along the lines suggested by Shiller, which minimizes the problems associated with faulty weighting of earnings.

Evidence-Based Technical Analysis

Posted by Peter on April 17, 2009
Posted in: Book Reviews, Investing. Tagged: .

Book review: Evidence-Based Technical Analysis: Applying the Scientific Method and Statistical Inference to Trading Signals, by David Aronson.

This is by far the best book I’ve seen that is written for professional stock market traders. That says more about the wishful thinking that went into other books that attempt to analyze trading rules than it does about this author’s brilliance. There are probably books about general data mining that would provide more rigorous descriptions of the relevant ideas, but they would require more effort to find the ideas that matter most to traders.

There hasn’t been much demand for rigorous analysis of trading systems because people who understand how hard it is to do it well typically pick a different career, leaving the field populated with people who overestimate their ability to develop trading systems. That means many traders won’t like the message this book sends because it doesn’t come close to fitting their preconceptions about how to make money. It is mostly devoted to explaining how to avoid popular and tempting mistakes.

Although the book only talks specifically about technical analysis, the ideas in it can be applied with little change to a wide variety of financial and political forecasting problems.

He is occasionally careless. For example: “All other things being equal, a TA rule that is successful 52 percent of the time is less valuable than one that works 70 percent of the time.” There might be a way of interpreting this that is true, but it’s easy for people to mistake this for a useful metric, when it has little correlation with good returns on investment. It’s quite common for a system’s returns to be dominated by a few large gains or losses rather than the frequency of success.

The book manages to spell Occam three different ways!

Chinese Stock Risks

Posted by Peter on December 11, 2008
Posted in: China, Investing.

There are lots of small Chinese companies trading on U.S. stock exchanges that look at first glance to be ridiculously underpriced. One reason for the low prices are that it’s harder than you might expect to enforce U.S. law on Chinese companies that have few or no assets in the U.S.

The most blatant example I’ve seen is Eternal Technologies Group Inc, which has ignored a judgment in a lawsuit that seems minor compared to the cash the company reports having, with the result that a receiver has been appointed who is likely to collect some money in ways that badly hurt stockholders who bought before the lawsuit.
Another hint at how little the company cares about stockholders (at least those in the U.S.) is the careless way their press releases are written: “5. Radification of the elecrion of the auditors” (they managed to spell election correctly on the prior line, so it’s not simple ignorance).

I’ve noticed problems with other U.S. traded Chinese companies that leave me uncertain which of them can be trusted. I’ve been trading stocks listed on the Hong Kong Stock Exchange a fair amount, and haven’t noticed any similar problems there. I presume the stronger cultural and/or legal ties are more effective than anything that can be accomplished by U.S. law.

Stock Market Crashes

Posted by Peter on November 1, 2008
Posted in: Investing. Tagged: .

Many people seem to be reacting to the recent stock market crash the way they wish they had to the 1987 crash, and a smaller number are comparing it to 1929.
The unusual resemblance to the crash of 1937 makes me expect something in between those two scenarios.

  • The 1937 crash was caused in part by a sudden increase in caution by banks after the Fed significantly increased their reserve requirement. Banks played no interesting role in the 1929 or 1987 crashes.
  • The 1929 and 1987 crashes followed stock market peaks in August, versus March and the prior October for the 1937 and 2008 crashes.
  • The 1937 and 2008 crashes both came eight years after one of history’s largest stock market bubbles.
  • The 1929 and 1987 crashes followed an increase in the discount rate to 6 percent. The 1937 and 2008 crashes followed decreases in the discount rate to 1 and 2.25 percent.

All four crashes happened mainly in October and their behavior in that month provides little reason for distinguishing them.
If the 1937 crash is a good model for what to expect in our near future, many investors who are currently following the lesson they learned from the 1987 crash will discover in early 2009 that the unexpectedly severe recession casts doubt on the belief that crashes create good buying opportunities. How many of them will stick to their buy and hold commitment then (when I expect it will be a good idea)?
When the extent of the recession becomes disturbing, remember Brad DeLong’s perspective:

Is 2008 Our 1929? No. It is not. The most important reason it is not is that Bernanke and Paulson are both focused like laser beams on not making the same mistakes as were made in 1929….
They want to make their own, original, mistakes..

(HT James Hamilton).

Misbehavior of Markets

Posted by Peter on October 5, 2008
Posted in: Book Reviews, Investing.

Book review: The Misbehavior of Markets: A Fractal View of Risk, Ruin & Reward by Benoit Mandelbrot.
Mandelbrot describes some problems with financial models that are designed to provide approximations of things that can’t be perfectly modeled. He pretends that pointing out the dangers of relying too much on imperfect approximations shows some brilliant insight. But mostly he’s just translating ideas that are understood by many experts into language that can be understood by laymen who are unlikely to get much value out of studying those ideas.
His list of “ten heresies” is arrogantly misnamed. Sure, there are some prestigious people whose overconfidence in financial models leads them to beliefs that are different from his “heresies”, but those “heresies” are closer to orthodoxies than they are to heresies.
His denial of the equity premium puzzle is fairly heretical, but his argument there is fairly cryptic, and relies on suspicious and poorly specified claims about risk.
He says market timing works, but the strategy he vaguely hints at requires faster reaction times than are likely to be achieved by the kind of investor this book seems aimed at.
His use of fractals doesn’t have any apparent value.
Mandelbrot is primarily a mathematician with limited interest in understanding how markets work. One clear example is his mention of a time when Magellan “was still a small fund, too small for any detractors to argue that its size alone gave it a competitive edge”. Any informed person should know that’s completely backward – larger funds have a clear disadvantage because they are limited to trading the most liquid investments.
Another example of a careless mistake is when he claims the evidence suggests basketball players have hot streaks, seemingly unaware that Tversky and others have largely debunked that idea.

Wall Street vs Intrade

Posted by Peter on September 29, 2008
Posted in: Idea Futures, Investing.

The stock market reacted to today’s defeat of the bank bailout bill with an unusually big decline. Yet the news wasn’t much of a surprise to people watching Intrade, whose contract BAILOUT.APPROVE.SEP08 was trading around 20% all morning. Why did the stock market act as if it was a big surprise?
Did Intrade traders make a lucky guess not based on adequate evidence? Did they have evidence that the stock market ignored? Could the stock market have priced in an 80% chance of the bill being defeated (if so, that would seem to imply that passage would have caused the biggest one-day rise in history)? Could the stock market have been reacting to other news which just happened to coincide with the House vote? (It looks like the market had a short-lived jump coinciding with news that House leaders hoped to twist enough arms to reverse the vote, but I wasn’t able to watch the timing carefully because I was at the dentist).

It seems like one of these must be true, but each once seems improbable.

Arnold Kling, whose comments on the bailout have been better than most, was surprised that the bill failed.

I covered a few of my S&P 500 futures short positions at near the end of trading, but I’m still positioned quite cautiously (I made a small profit today).

Moral Hazard with Credit Default Swaps

Posted by Peter on September 17, 2008
Posted in: Investing.

Charlie Munger in the August 31, 2008 issue of Outstanding Investor Digest:

Let’s say you’re insuring against the outcome that people will lose money on a $100 million bond issue, and the credit default swaps, instead of amounting to $100 million, amount to $3 billion. Now you’ve got people with $3 billion worth of contracts that really have a big incentive in having somebody fail. And they may manipulate in some fraudulent or extreme way to cause a default in order to make the big collection.

There doesn’t seem to be enough transparency in financial systems to figure out whether this concern is relevant to this week’s panic.

Oil Volatility

Posted by Peter on August 28, 2008
Posted in: Investing.

News reports plus the pattern of crude oil fluctuations indicate that the large price increases around May and June were due mainly to Chinese desperation to guarantee a larger than normal margin of safety during the Olympics, not manipulation (although the results bear a good deal of resemblance to the results of manipulation).

Negative Interest Rates

Posted by Peter on May 11, 2008
Posted in: Investing. Tagged: .

For more than 2 months, Treasury Inflation-Indexed Notes maturing within 2 years have been selling at prices that apparently mean their yields are negative (e.g. see here and here). This isn’t the first time people have apparently paid a government to hold their money, but I can’t think of a previous case where yields reached -1 percent.
What can cause such a perverse situation? An expectation that the CPI would overstate inflation by as much as 1 percent would mean appearances are misleading and investors do expect to make money on those notes. I could make a case for that by focusing on the way that the CPI’s reliance on rents to measure housing costs hides the effects of dropping home prices. But most evidence about people’s inflation expectations (e.g. the University of Michigan Inflation Expectation report) say they expect more inflation than what can be inferred from the Treasury Inflation-Indexed Notes about expected CPI change.
So I’m inclined to conclude that we’re seeing investors paying abnormally large amounts in order to get liquidity, and probably plan to redeploy those assets somewhere else within a few months. If we see a big financial crisis soon, that strategy may pay off. But having people prepare for financial crises tends to reduce their magnitude, so I’m skeptical and am short t-bond futures.