BYD Stock Sale Is an Old-School Value-Investing Move by Buffett

When Berkshire Hathaway Inc. started trimming its stake in BYD Co., theories swirled about the prospects for China’s largest electric-vehicle maker. Turns out, it’s less about the company and more about Warren Buffett being Warren Buffett.

Berkshire has begun shedding BYD stock, dragging down the firm’s shares as traders feared an exit by its most notable backer. For BYD, with profit that just tripled and a nearly 30% share in China’s expanding electric-car manufacturing market, the stock sales struck some as puzzling.

But the share sales probably don’t reflect concerns about BYD’s fundamental business, and rather underscore the billionaire ...