Berkshire Hathaway trades by members of Congress

When several House members traded Berkshire Hathaway

Months when 2 or more House members became net buyers, or 3 or more net sellers, of Berkshire Hathaway in reports dated in the 91 days before the month end, and how the stock did against the S&P 500 from that month end. Only House members' electronic trade reports are included; Senate reports and reports filed on paper are not. After the 10 buying crowds with six months of prices, it averaged −0.9% against the index. After 7 selling crowds, −2.7%. One company's history is too short to judge by; the test across every company is the better guide.

Colours show whether the crowd was right: green when buyers were followed by a rise above the index, or sellers by a fall below it. Latest 12 of 19. Total returns from the month end; past patterns are not a forecast.