Steven A. Ballmer believes in Twitter. And he looks to be putting his money where his mouth is.
In a tweet sent on Thursday evening, Mr. Ballmer, the former chief executive of Microsoft, said he had acquired a 4 percent stake in Twitter, becoming one of the single-largest outside shareholders of the company. He also praised one of the company’s new products, Moments, which organizes tweets on specific topics.
A source familiar with the matter, who spoke on condition of anonymity, confirmed that the Twitter account belonged to Mr. Ballmer.
The vote of confidence comes after a long year for the embattled company. User growth for the company has slowed, its share price has fallen sharply and it has lost many high-profile employees. Investors and analysts have worried that unlike Facebook, Twitter may not be able to expand far beyond the more than 316 million people who now use it each month.
A spokesperson for Mr. Ballmer did not immediately respond to a request for comment.
Mr. Ballmer joins a small cadre of outside owners of a large number of Twitter shares, including Rizvi Traverse Management, which owns less than 5 percent, as well as Morgan Stanley, which owns 4.54 percent of the company. Kingdom Holdings, the investment arm of the Saudi Arabian prince, Alwaleed Bin Talal, recently increased its stake in Twitter to more than 5 percent.
Mr. Ballmer’s ownership stake appears to be even more than Jack Dorsey, Twitter’s co-founder and newly named chief executive, who owns a 3.2 percent stake in the company. Evan Williams, Twitter co-founder and board member, remains the single largest shareholder, with a roughly 6.9 percent stake.
Shares of Twitter jumped 5 percent on Friday, to $31.15. Twitter stock is down more than 38 percent over the last year.
(Published by October 16, 2015)