Microsoft's stock closed up more than 3% on MondayBeijing, April 23rd - Microsoft's stock price closed up by over 3% on Monday, hitting a 7-month high during the session, mainly due to reports that a hedge fund had purchased $2 billion worth of Microsoft shares.On the day, Microsoft's stock rose $1.04 in regular Nasdaq trading, closing at $30.80 per share, an increase of 3.48%. It reached as high as $31.18 during the session, a rise exceeding 4%, marking the highest level since last September. Over the past 52 weeks, Microsoft's highest price was $32.52 and its lowest was $26.26. In the last two trading days, Microsoft's stock has risen approximately 7.5%. So far this year, Microsoft's stock has increased by 16%, potentially setting its best annual performance since 2009. However, Microsoft investors have complained that compared to 11 years ago, the company's stock price has remained largely unchanged.Microsoft's stock began rising from early Monday morning due to CNBC reporting that the activist investment firm and hedge fund ValueAct Capital had invested $2 billion in purchasing Microsoft shares. Based on Friday’s closing price, this $2 billion investment equates to 67.2 million shares of Microsoft stock. Although this represents less than 1% ownership, it is still enough to make ValueAct Capital one of Microsoft's top 15 investors. A spokesperson for ValueAct has not yet commented on this matter.Over the past decade, Microsoft and its CEO Steve Ballmer have become targets of much criticism, primarily because the company lagged behind Apple and Google in the market shift towards mobile computing. However, Microsoft has not significantly become a target of noticeable shareholder protests. The most recent public challenge for the company occurred two years ago when David Einhorn of Greenlight Capital demanded Ballmer's resignation. At the time, Einhorn stated: "The biggest risk to Microsoft's stock price is that Ballmer continues to run the company."Microsoft never publicly responded to Einhorn's remarks, but Ballmer said he did not plan to leave, intending to remain as CEO for at least another four to five years. Subsequently, Greenlight Capital reduced its stake in Microsoft. By the end of last year, Greenlight Capital's holdings amounted to only 0.13% of Microsoft's total outstanding shares.For Microsoft, any internal attempt to force changes would likely face opposition from its largest shareholder, Chairman and co-founder Bill Gates, who still owns 5% of Microsoft's shares. Ballmer, as the third-largest shareholder, holds about 4% of the shares.