Reconciling "Random Walk" with "Market Wizards"

[eastbay]

I just read two books. The first was "Market Wizards" which is a series of interviews with successful traders, and as one example features a guy who entered a 4-month trading contest and won 9 out of 10 times by a large margin each time, by the name of Marty Schwartz.

And yet, on page 245 of "A Random Walk Down Wall Street", Malkiel makes the somewhat astonishing assertion that:

No one person or institution has yet to produce a long-term, consistent record of finding money-making, risk-adjusted individual stock-trading opportunities.

Now, I guess the catch-all "out" for this statement is "long term" and possibly "risk adjusted" although it's unclear to me what he means by that latter. But whatever example you point to, you could always just say "Not long term enough." But the claim in Market Wizards is that Schwartz has produced "enormous percentage gains every year since 1979." Now that's a somewhat vague statement, but it certainly sounds like a counterexample to Malkiel's assertion.

In any case, how can Malkiel make a statement like this if guys like Marty Schwartz really exist and really get the results they claim to?

There's really only two possibilities here: the so-called "Market Wizards" are frauds, or Malkiel is wrong.

Which do you think is closer to the truth?

eastbay

[Soxx Clinton]

Warren Buffett made an interesting comment about trader performance records with his famous "coin flipping contest" argument. ie. Even with millions of participants in a huge tournament someone will still win the tournament. Does that make the winner an expert coin flipper?

That said, having read both books, and being a portfolio manager by trade, I think that there is a grey area in between the two books. I think it is possible to beat the market (and have consistently done so myself) but like anything else worthwhile, it is fairly difficult to do, is a lot of work, and takes a certain disposition.

For most people I think trading is -EV. This is confirmed by the numerous studies on retail trading accounts, mutual fund performance, day-trader failure rates, and even independent floor traders who constitute a hugely motivated and full-time group.

In other words, who wants to spend hours a day working on trading when you only have a ~10% chance of beating the market. Of those ~10%, how many beat the market by say double-digits per annum? If not, does the extra 5% a year compensate for the time, training, and stress of just holding the SPY's which if you hold them long enough are an almost sure thing?

[eastbay]

[ QUOTE ]
Warren Buffett made an interesting comment about trader performance records with his famous "coin flipping contest" argument. ie. Even with millions of participants in a huge tournament someone will still win the tournament. Does that make the winner an expert coin flipper?


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Obviously not, but I think the analogy is poor.

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That said, having read both books, and being a portfolio manager by trade, I think that there is a grey area in between the two books. I think it is possible to beat the market (and have consistently done so myself) but like anything else worthwhile, it is fairly difficult to do, is a lot of work, and takes a certain disposition.


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That seems clear enough.

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For most people I think trading is -EV.

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True. For most people playing poker is -EV, too. But that's hardly evidence that poker is unbeatable (even though many will insist that it is).

[ QUOTE ]

In other words, who wants to spend hours a day working on trading when you only have a ~10% chance of beating the market. Of those ~10%, how many beat the market by say double-digits per annum? If not, does the extra 5% a year compensate for the time, training, and stress of just holding the SPY's which if you hold them long enough are an almost sure thing?

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I guess it depends. Primarily on how much money you're getting the 5% on.

eastbay

[Soxx Clinton]

The point of the coin flipping example is that looking back in hindsight, six sigma traders are inevitable. I think this is ultimately how the two books reconcile somewhat. One could argue that Schwager is guilty of "data-snooping".

Don't get me wrong- I certainly wasn't making the case that the market is unbeatable. I think it is for the people with right skills, mindset, and work ethic. Fortunately for me, these people are pretty unusual. [img]/images/graemlins/wink.gif[/img]

[edtost]

[ QUOTE ]
No one person or institution has yet to produce a long-term, consistent record of finding money-making, risk-adjusted individual stock-trading opportunities.

[/ QUOTE ]

Let's expand the quote a bit and see if his statement makes a little more sense:

"What Do We Mean by Saying Markets Are Efficient?

I'd like to relate it to a well-known story that tells of a finance professor and a student who comes across a $100 bill lying on the ground. As the student stops to pick it up, the professor says, "Dont't bother--if it were really a $100 bill, it wouldn't be there."
[...]
While there are some who agree that there areno $100 bills lying around, an even greater number insist that there's still lots of loose change. The debate on just how much loose change there is, and whether there is any dependable way to pick it up, is a subject that has made many academic careers.
[...]
No one can consistently predict either the direction of the stock market or the relative attractiveness of individual stocks and thus no one can consistently obtain better overall returns than the market. And while there are undoubtedly profitable trading opportunities that occasionally appear, these are quickly wiped clean once they become known. No one person has yet to produce a long-term, consistent record of finding money-making, risk adjusted individual stock-trading opportunities, particularly if they pay taxes and incur transactions costs" (Malkiel 244-5, emphasis added in bold)

Note that Malkiel's book is about things that small individual investors can take advantage of - unless this Marty Schwartz was a mutual fund manager, using his strategies would likely result in prohibitive trading costs for a small investor.

Also, optimal strategy to make it likely for him to win a 4-month contest probably includes taking on an absurd amount of risk, much greater than what the average reader of Malkiel's book is willing to expose themselves to.

[Paluka]

[ QUOTE ]
[ QUOTE ]
Warren Buffett made an interesting comment about trader performance records with his famous "coin flipping contest" argument. ie. Even with millions of participants in a huge tournament someone will still win the tournament. Does that make the winner an expert coin flipper?


[/ QUOTE ]

Obviously not, but I think the analogy is poor.

[

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I don't think the analogy is that far-off. My experience is that a good portion of the people profiled in the Market Wizards books are the "coin flippers" who got lucky. There are some notable exceptions, including the guy I work for.

[eastbay]

[ QUOTE ]
No one person has yet to produce a long-term, consistent record of finding money-making, risk adjusted individual stock-trading opportunities, particularly if they pay taxes and incur transactions costs[/i]" (Malkiel 244-5, emphasis added in bold)

Note that Malkiel's book is about things that small individual investors can take advantage of - unless this Marty Schwartz was a mutual fund manager, using his strategies would likely result in prohibitive trading costs for a small investor.


[/ QUOTE ]

The Market Wizards book is mostly guys who started with a few tens of thousands of dollars or less. Marty started with $20k in the 70s, which is a substantial amount but not totally out of reach of ALL individual investors (remember, Malkiel's statement says NO ONE.)

Second, if Malkiel is going to make such a huge assertion, he should qualify it appropriately. He did not say "no one without N$." He did not say "no one without experience". He said NO ONE. I think the statement is plainly false by counterexample. Warren Buffett?

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Also, optimal strategy to make it likely for him to win a 4-month contest probably includes taking on an absurd amount of risk, much greater than what the average reader of Malkiel's book is willing to expose themselves to.

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Maybe, but 9 wins out of 10 is at least partial evidence that the risk was worth the reward.

eastbay

[judgesmails]

I agree with Malkiel on his statement but I don't totally buy into the random walk theory.

Nor do I believe that Schwartz has produced "enormous percentage gains every year since 1979." That is simply impossible in literal terms.

John Allen Paulos does a great job of laying out many market theory's in his book "A Mathematician Plays the Stock Market." One point that he makes that I have really carried with me since reading it is that many market "gurus" like Buffett, Peter Lynch, or John Neff have an effect on the market and their stock choices can become self-fulfilling after a short-term period of success. That is, the market will follow them and prop up their moves.

I sincerely doubt there are many individual traders out there with a 10 year record of beating market performance by ten percent.

[RunDownHouse]

There is no "lead steer" in the market, although this theory used to be popular, and still is to some people.

[DesertCat]

[ QUOTE ]


John Allen Paulos does a great job of laying out many market theory's in his book "A Mathematician Plays the Stock Market." One point that he makes that I have really carried with me since reading it is that many market "gurus" like Buffett, Peter Lynch, or John Neff have an effect on the market and their stock choices can become self-fulfilling after a short-term period of success. That is, the market will follow them and prop up their moves.

[/ QUOTE ]

This is patently false when it comes to Buffett. He wasn't even well known until the 80's but had beat the market almost every year since the mid-50s. Since he's become a "rock star" his level of outperformance has actually declined, but that's primarily due to the enormous size of his portfolio dragging down his returns.

Buffett's success is basic value investing principles, he buys undervalued securities. He's just been at it a bit longer, and is a bit better at it, than all the other value investors.