The Bill and Melinda Gates Foundation has significantly reduced its stake in Microsoft, selling approximately 17 million shares, which accounts for nearly 65% of its holdings in the company. The sale, which took place in the third quarter of 2025, was revealed in a recent 13F filing and is valued at around $8.7 billion. The move is reportedly part of a broader portfolio rebalancing strategy and to fund the foundation's philanthropic activities. This large transaction has been described as a surprise to the market, given that Microsoft has traditionally been the foundation's most significant and stable investment. The sale has reportedly caused a 17.7% decrease in the value of the foundation's portfolio. Despite this substantial sale, the foundation continues to hold a significant number of Microsoft shares, indicating a continued relationship with the tech giant.