According to the numbers on eHow, the first day arithmetic returns (relative to IPO price, not the opening trade price) were, at close: (27.75-21) / 21 = 32.1%,

According to the numbers on eHow, the first day arithmetic returns (relative to IPO price, not the opening trade price) were, at close: (27.75-21) / 21 = 32.1%, and at day's peak: (29.25-21) / 21 = 39.3% The prices I used are from a site on eHow: http://www.ehow.com/about_5077008_microsoft-stock-split-history.html http://www.ehow.com/about_5077008_microsoft-stock-split-hist...