BYD Company Ltd shares plunged last week for reasons that are unclear, but at least one major investor took advantage of the sharp decline. Himalaya Capital Investors purchased an additional 3.2 million shares in the Chinese electric bus maker on Thursday. That was the same day as the mysterious share price plunge which dragged shares down 40%.

Shares of BYD have partially recovered since then, but they still remain lower than where they were before the sudden decline in price.

Li Lu adds to BYD position

Forbes staff writer Heng Shao reports on the position increase, citing a regulatory filing. Li Lu controls Himalaya Capital through his firm LL Group, Himalaya’s parent company. LL Group is BYD’s controlling shareholder, owning approximately 2.4% of the company’s outstanding shares, which amounts to about 57.4 million.

Li was once rumored to take over part of Warren Buffett’s portfolio. He was one of BYD’s earliest investors, and his firm’s website states that they have been invested in the company for more than a decade.

BYD

Buffett not selling BYD shares

Later he was invested in BYD through a fund with investment from Buffett wingman Charlie Munger. After that, Munger convinced MidAmerican Energy Holdings, a Berkshire Hathaway Inc. subsidiary, to purchase a 10% stake in BYD. One of the suggested reasons for last week’s stock price plunge was a rumor that Buffett’s firm was planning “to sell a substantial amount” of its shares in BYD.

Shortly after that rumor began circulating, BYD issued a statement saying it had “communicated and confirmed with the relevant person-in-charge” of Berkshire. The statement added that the rumor about “the intention to reduce shareholdings in the Company [BYD] is not correct and that it has no present intention to reduce shareholdings in the Company.”

Why did BYD shares plunge?

Last week analysts from several firms issued reports with their speculations about why BYD shares suddenly plummeted. In addition to the rumor about Berkshire possibly selling some of its stake in BYD, there were concerns about cuts in electric bus orders. Those concerns are related to government subsidies on electric buses, although JPMorgan analysts said their checks suggest the Chinese government will keep its subsidy policy in place at least until next year and even after 2016.

Another suggestion was that the Russian economy was weighing on BYD, but the company has very limited exposure to Russia.