According to regulatory documents, Warren Buffett's Berkshire Hathaway subsidiary, Berkshire Hathaway, has been buying Western Oil stocks every day for nine consecutive trading days, with the latest holding percentage reaching nearly 29%. Three documents show that Berkshire was on June 5th, 6th, and 7th; On the 10th, 11th, and 12th; And on the 13th, 14th, and 17th, they purchased Western Oil stocks, with a total of 7.3 million shares purchased during these nine trading days, at a trading price around $60 per share.