Buffett’s best-ever trade may be his move into tech giant Apple, which earned Berkshire Hathaway $40 billion since the market bottomed in March. This according to a recent article in CNBC.

“Berkshire Hathaway’s Apple stake—which has claimed 40% of its equity portfolio—is up a whopping $40 billion since the market bottom in March,” the article reports, adding, “The investment in the tech giant played a crucial role in helping the conglomerate weather the coronavirus crisis as other pillars of its busines, including insurance and energy, took a huge hit.”

Buffett’s investment in Apple contrasted with his long-standing aversion to tech stocks, the article notes, adding that Berkshire purchased its first 10 million shares in the tech behemoth in May 2016 through one of Buffett’s lieutenants. In a four-year period, the article notes, he increased his bet “245 million shares, now worth more than $95 billion, to become Apple’s second largest shareholder, only behind Vanguard.”

Before dipping into the tech space, Berkshire’s stock portfolio was concentrated in financials and consumer businesses. Today, Buffett refers to Apple as Berkshire’s “third-largest business” after insurance and railroad holdings. “It’s probably the best business I know in the world,” Buffett told CNBC in February.

While many on Wall Street are cautious about the high valuations of tech companies, the article suggests it’s unlikely Buffett will be selling his Apple shares anytime soon.