The Paradox Of Provable Alpha

The reason for this short post is there’s an idea I’ve formulated in a couple of places that I just wanted an isolated link to.

From Why I Share Online And The Decision To Leave Trading:

An aside that is gonna trigger some set of people: I could hand over all my professional dashboards and tools, and it wouldn’t make a difference. You won’t get the same results. Experience, discipline, and creativity are not something you can take from another. And they are foundational to a discretionary strategy. Think about this from a game-theoretic point of view. If I could codify (I tried and couldn’t) what I did, then it would be easy to prove the edge. The strategy would then be automated and be oversubscribed or its owners would never sell it to an investor. The fact that it’s discretionary and cannot be proven except by its eventual outcomes means an investor must always worry that I’m full of shit.

Do you see the paradox?

If the edge is provable, it doesn’t exist for you. So the only hope of finding edge is in your judgment of a discretionary strategy.


From Trading Vs Investing:

Since the compounded return of an investment depends on how a company re-invests, it requires distant foresight into an inherently complex system. Long-term investing, like long-term weather forecasting, has an irreducible bar of uncertainty that sits unpleasantly high off the ground. There’s only so much you can say about a system governed by chaos, biological, and evolutionary forces as opposed to tidy physical properties. Feedback loops are long, causation is opaque, and the signal-to-noise ratios are too low to prove an edge. This leads to a paradox. If a manager’s edge is unprovable, then there’s a chance you can actually access it, you’ll just understand it post-hoc. If the edge was provable, the manager would extract all the excess alpha for themselves by either choosing strategic investors or charging ransom fees.


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