Berkshire Hathaway Inc.’s market value increasingly comes from an industry that billionaire Warren Buffett basically shunned for decades: technology. Berkshire’s stake in Apple Inc. was valued at $91.4 billion as of Tuesday, according to data compiled by Bloomberg. That’s equivalent to 21% of the market value of Buffett’s company, up from 13% at the start of 2020. The calculations are based on the 245.2 million shares of Apple that the company owned last Dec. 31 and on March 31. Berkshire has held a stake in the iPhone maker since the fourth quarter of 2016.