Microsoft invested $150 million into Apple on August 5, 1997 (convertible preferred nonvoting stock which ultimately converted into 18.2 million shares of common stock). Bill himself appeared on satellite link at Macworld (1997!). 18.2 million shares today is $4.9 billion (split-adjusted).
I can't find when exactly Microsoft sold their shares, but it was sometime during 2003. Wolfram Alpha calculated the mean price of AAPL in 2003 was 9.26 (max 12.41 min 6.56), which is split-adjusted. The real price then would be 18.52 (mean). One split would have happened, so 36.4 million shares were owned by MSFT at the time of sale, so they sold for a mean of $674 million.
Someone check my math? It's 5am. It's difficult because a lot of the sources I used don't denote whether a price is split-adjusted or not, and Microsoft converted portions of stock at different times. It's a mess.
Great analysis. I will note that however much money MS lost or made on the deal, the value of maintaining a customer platform (for Office) and keeping a competitor alive (at a time when the antitrust thing loomed) was probably priceless.
Maybe at the time Microsoft saw Apple as a dying company that would never recover from their early to mid-90s blunders, so throwing it a bone would have seemed like a no brainer at the time.
I may be misunderstanding, but it looks like you're giving them both the post-split number of shares and pre-split price, which would double the value of the investment? Great number sleuthing, though, thanks!
Oh, on reread - perhaps the stock split in 2003 would have been the second time?
