Microsoft reached a corporate milestone at the end of April when its long-time largest individual shareholder Bill Gates continued selling his shares to raise funds for his foundation Bill and Melinda Gates. The company's founder and former CEO has been selling his shares at about 80 million yearly, to fund philanthropic works in global health and education through his foundation.

For the first time, Gates' 330.1 million shares are now outnumbered by others, specifically by immediate past CEO Steve Ballmer, who owns 333 million shares. When Satya Nadella succeeded Steve Ballmer, Gates let go of his position as chairman, saying he will spend more time as Microsoft's adviser.

The April 30 transaction involved 4.6 million shares sold at $40.34, bringing Gate's ownership to less than 4 percent of Microsoft. Gates has been the company's largest shareholder since mid-1970s. He was mentioned in his colleague's 2011 memoir, Microsoft co-founder Paul Allen as convincing him (Allen) to take the 40 percent of Microsoft partnership, when he originally thought it was a 50-50 split with Gates. Later, Gates convinced him again to change the split to Gate's favor, 64-36.

Meanwhile, Ballmer's 333 million shares is 4 percent of the entire Microsoft firm. When Ballmer announced his plan to retire on August 2013, he told Microsoft employees through an email he cherishes his ownership of the Redmond company, and looks forward to continue being among its largest owners.

Ballmer's Microsoft ownership remains intact as he never sold a single share after he stepped down in February.