From the SEC:

On November 12, 2010, Jerry Yang, co-founder and Chief Yahoo of Yahoo! Inc. (“Yahoo!”), transferred 2.5 million shares of Yahoo! common stock to a blind trust managed by a third-party trustee who will have complete discretion as to when, and to what extent, the stock is to be sold or otherwise disposed.

The trust is scheduled to terminate by December 31, 2011. The blind trust is intended to comply with Rule 10b5-1 under the Securities Exchange Act of 1934, as amended, and Yahoo!’s Rule 10b5-1 Trading Plan Policy.