Problem bank

Problem 261 of 333HardFinanceP261

Kelly weights for two correlated stocks

  1. Two stocks have expected excess returns of 6% and 4% a year, volatilities of 20% and 15%, and correlation 0.5. With continuous rebalancing, the expected log growth rate of a portfolio holding weights ww (fractions of wealth, leverage allowed) is g(w)=r+w⊤μ−12w⊤Σwg(w) = r + w^\top \mu - \frac12 w^\top \Sigma w. Find the growth-optimal weights, show they are a maximum, and compare them with the Kelly weight for each stock on its own.