AP Images

Warren Buffett sold more than $800 million in Apple stock last quarter, new SEC filings show.

The Berkshire Hathaway CEO is Apple's biggest shareholder with a 5.4% stake worth $72 billion.

Buffett's lieutenants may have sold the shares to free up cash to invest in Kroger and Biogen.

Apple stock has skyrocketed 90% in the past year.

Visit Business Insider's homepage for more stories.

Warren Buffett sold more than $800 million worth of Apple stock last quarter, according to SEC filings published on Friday.

That might seem like a massive sale, but it's closer to a rounding error for the billionaire investor and Berkshire Hathaway CEO. Berkshire is Apple's biggest shareholder with a 5.4% stake worth $72 billion, according to Bloomberg data.

Buffett's lieutenants may have trimmed their stake in Apple for a few reasons. Perhaps they wanted to diversify Berkshire's holdings, given the iPhone maker accounts for nearly 30% of its portfolio. Indeed, Berkshire made fresh investments in Kroger and Biogen last quarter.

Alternatively, they may have wanted to cash out after Apple's stock surged by a third last quarter, from roughly $219 to $294. Depending on when they sold the 3.7 million Apple shares, they netted between $806 million and nearly $1.1 billion.

Buffett is unlikely to sell a significant amount of his Apple shares anytime soon, given his preference for long-term investing over a quick payday. He's also unlikely to buy more.

The so-called "Oracle of Omaha" balked at buying Apple shares when they were trading at $175 a year ago. "If it were cheaper, we'd be buying it," he said in a CNBC interview in February 2019. "We aren't buying it here."

The stock has skyrocketed more than 85% to $325 since then, boosting Apple's market capitalization to more than $1.4 trillion.

NOW WATCH: A big-money investor in juggernauts like Facebook and Netflix breaks down the '3rd wave' firms that are leading the next round of tech disruption