Steve Ballmer, the former Microsoft CEO and current Los Angeles Clippers owner, is now one of the largest outside shareholders in Twitter.

screenshot from CBS This Morning YouTube video

In a tweet sent very early this morning, Ballmer wrote that he bought a 4 percent stake in the company. He also praised Moments, a new Twitter feature that organizes messages on specific topics.

According to The New York Times, there are only a few outside owners with chunks of Twitter stock. Rizvi Traverse Management has less than 5 percent and Morgan Stanley owns 4.54 percent. Saudi Arabia’s Prince Alwaleed Bin Talal also owns over 5 percent. Twitter co-founder Evan Williams has the most shares with a 6.9 percent stake in the company.

Ballmer’s decision comes at a rough time for the company. After being named permanent CEO, co-founder Jack Dorsey laid off over 300 employees and the company’s stock has taken a significant hit this year. Many think that Twitter will struggle to grow, but clearly Ballmer thinks the company is doing something right.