Microsoft’s Initial Public Offering took place on March 14, 1986 (or it was the first trading day). The stock, which eventually closed at $27.75 a share, peaked at $29.25 a share shortly after the opening. Microsoft’s two founders – Bill Gates and Paul Allen – were made instant millionaires by the offering, but they didn’t seem fazed by all the hoopla. Allen went to work as usual at Asymetrix, the company he founded the year before in Bellevue. Gates was in Australia on business. At that time, Bill Gates owned 45 percent of the company’s 24.7 million outstanding shares and Paul Allen owned roughly 25 percent of the shares.  Gates’ Microsoft stake was $233.9 million at the time of Microsoft’s 1986 IPO, making Microsoft’s total-value worth $519,777,778 at that time (1986).