Well, fancy that!

Between 1993 and 1998, the stock portfolio of the average household gained, on average, 1.4% less than the market as a whole. That is, most people’s portfolios grew by a bit less than (say) the SP 500.

Corporate insiders did better, managing to get gains of 5% above the market average. Regular stockbrokers without inside knowledge are lucky to match the market; only about quarter of managed funds beat index funds.

US Senators, however, managed to beat the market by a staggering 12% per year between ’93 and ’98.

It’s almost as though something sleazy happened, like Senators arranging legislation to boost their stock portfolio or engaging in endless insider deals with top businessmen. But of course, the truth is that the Senate is just filled with people of rare financial insight and acumen, paragons of fiscal probity who can achieve results an expert stockbroker can only dream of.

And Martha Stewart is innocent.