Warren Buffett’s Berkshire Hathaway reported late Thursday that it had purchased another 901,774 shares Occidental Petroleum common shares for $57.32-$57.34 in a filing.

This latest acquisition brings the stake up to 143,162,392 shares common and 100,000 Series-A Preferred shares.

It was worth $51.7 million, and its common stock component is currently valued around $8.5 trillion.

Occidental shares have increased by 104% over the past year, and the stock is down 17.5%.