Better returns alone aren't indicative of out-performance. What you would want to look at instead of returns is the Sharpe ratio of Hathaway and the market vs e

Better returns alone aren't indicative of out-performance. What you would want to look at instead of returns is the Sharpe ratio of Hathaway and the market vs each senator. The Sharpe ratio is the excess return (return minus the risk free rate, usually the yield on a 3 month T-note), divided by the volatility of the excess return. Another metric to look at would be each senators beta exposure and their R2: what percent of their returns are generated by their market exposure.