The recent investment that Warren Buffett’s holding company Berkshire Hathaway (BRK-A) made in Apple has paid off to the tune of hundreds of millions of dollars in value.

Shares of Apple (AAPL) have reached a record high, nearing $135 in afternoon trading Tuesday. The company has been on a tear since announcing better-than-expected quarterly earnings on January 31; its stock price has shot up more than 10% in the last two weeks.

In August, Berkshire disclosed it held 15.22 million shares of Apple, which amounted to around a $1.6 billion stake at the time. Given Apple’s recent surge, the stake is worth about $2.04 billion, a gain of roughly $400 million.

Berkshire, which has traditionally avoided technology stocks, started to amass a holding in Apple in the first quarter of 2016, when it bought just over 9.8 million shares. Berkshire then added 5.4 million more to its portfolio in the second quarter. At that time, taking on a bigger stake in Apple seemed like a potential misstep: The company’s stock had been swooning amid three straight quarters of profit and revenue declines due to decreases in iPhone sales.

Shares dropped to $90.25 in the middle of May, which caused big-name investors like George Soros and David Einhorn to sell off some or all of their holdings. But with the benefit of hindsight, it seems that Buffett – who has credited two of his deputies, Todd Combs and Ted Weschler, with selling him on Apple – saw a good deal and took advantage. Apple’s stock rebounded within a couple months, once again surpassing the $100 mark in late July, and has been off to the races ever since.

Buffett, who is one of the richest men in the world and worth $74.3 billion, according to Forbes, traditionally has an investing strategy centered on stable companies that sell consumer staples and will be around for many years. Berkshire’s A-class stock has a gargantuan valuation, coming in at $249,150 per share.

The fact that Buffett is betting on Apple is most likely a good sign for the iPhone maker, not that it needs the help. Apple is a behemoth in the stock market, with a market cap of around $700 billion. That makes it the most valuable company listed, more than $120 billion ahead of the second-place company, Google parent Alphabet.