The Cyclically Adjusted Price to Earnings Ratio, also known as CAPE or the Shiller PE Ratio, is a measurement from […]

Remember a few weeks back when we discussed stock market investing using the Kelly Criterion to determine asset allocations? Today we're going to go in a different direction and use Kelly for what it was intended - betting!

The Kelly Criterion is a formula you can use to determine the proper size of a bet when there are known odds and a definite payout. With a little hand waving and some basic math (as I proved a few weeks back), you can also use it to help guide your investment decisions - namely when determining the size of a position you should take. Let's hop into some calculators.

The Kelly Criterion is the brilliant summation of a betting strategy first discovered by Information Theorist John Kelly. Kelly came up with a betting system, his criterion, which optimizes bankroll growth based upon known odds and a definite payout. Roughly, if you can find an exploitable, repeatable edge... Kelly's system tells the maximum you should bet based upon that criteria.