Bill Gates has seen the future, and in his investing opinion, it's health care. At least that's what recent public filings by Microsoft may indicate. The software giant's chairman has unloaded 9 million Microsoft shares--valued at more than $463 million--since the beginning of August. That includes 2 million shares he sold this week, according to a Securities and Exchange Commission document. As of June, Gates held 660 million Microsoft shares.

At the same time, Gates, widely heralded as a trend-predicting savant, has been loading up on biomedical and health-care stocks. In the second quarter, he bought 2,589,000 shares of Prozac-maker Eli Lilly & Co. He also acquired 1,339,000 shares of Merck & Co., and 1,202,000 shares of Pfizer Inc.