Twitter has seen a big investment from Steve Ballmer, a former Microsoft CEO and owner of the NBA’s Los Angeles Clippers. Ballmer, via his newly created Twitter account that was immediately verified, said he has taken an ownership stake in the micro-blogging firm.

Ballmer Now Twitter Inc's Third-Largest Investor

Ballmer now third-biggest investor in Twitter

“Good job @twitter,@twittermoments innovation, @jack Ceo, leaner, more focused. Glad I bought 4% past few months. Like @alwaleedbinT move too,” Ballmer tweeted. At current valuation, Ballmer’s investment would amount to around $840 million, reported Bloomberg.

With the investment, Ballmer has become the third-biggest investor in Twitter, and his stake is even greater than that of the new CEO Jack Dorsey, who owns 3%, says a report from CNET. Co-founder Evan Williams with 6.8% is the biggest shareholder of the San Francisco-based micro-blogging company.

Ballmer’s high-profile investment comes at a time when Twitter is trying to add more users to its platform. The company recently unveiled a new feature ‘Moments.’ Twitter is also working to make the platform more accessible and broaden its appeal with packages of commentary, video and photos about major events.

A Twitter spokesman confirmed to CNET that the verified account belonged to Ballmer, but he could not confirm the investment. Ballmer was not available for comment immediately.

Ballmer in favor of workforce reduction

Ballmer praised the new CEO and also Saudi Prince Alwaleed bin Talal. The latter increased his stake in Twitter to more than 5%. Ballmer’s move and his comments suggest that he believes there is a new momentum in Twitter. How active Ballmer will be as an investor is not clear for now, but imagining him ever being passive is difficult.

Twitter slashed its workforce by 8% last week, and Ballmer believes this is a good move. Wall Street’s reaction to Ballmer’s own investment was positive as reflected by the rise of around 3% in the company’s shares upon his announcement.

Ballmer’s Twitter account shows a fairly conservative spread of interests. He is following 24 people, among whom four are Clippers players, one is LeBron James and another is Dallas Mavericks owner Mark Cuban. Other names include golfer Jordan Spieth, Microsoft co-founder Paul Allen and the White House. It is worth noting that he is not following Bill Gates.

In pre-market trading today, Twitter shares were down 0.22% at $31.08. Year to date, the stock is down over 13%, while over the last year, it is down over 36%.