OMAHA, Neb. (Reuters) – Warren Buffett stated Saturday that Berkshire Hathaway Inc took a 9.5% interest in Activision Blizzard Inc. (NASDAQ:). The majority of this stake was acquired after Buffett retired. Microsoft Corp (NASDAQ) purchased the video game manufacturer for $68.7 Billion.

Berkshire previously revealed that it owned a smaller Activision share, which was purchased by one the portfolio managers who helped Buffett invest Berkshire’s money.

Buffett stated at Berkshire’s annual conference that he was the one responsible for additional investments and that Berkshire would submit a report to regulators if Activision stakes exceed 10%.

Berkshire revealed earlier Saturday that it had spent $51 billion in equities during the first quarter.

Multibillion-dollar investments were made in this year’s oil companies by the company. Chevron Corp (NYSE -) and Occidental Petroleum Corp (NYSE –), and computer printer manufacturer HP Inc (NYSE –).

Berkshire agreed to $11.6 billion cash payment in March for Alleghany Corp.