Berkshire Hathaway added approximately $17 billion to its Alphabet position during the second quarter, making Google’s parent company the third-largest holding in Berkshire’s equity portfolio.

According to Berkshire’s second-quarter portfolio filing with the U.S. Securities and Exchange Commission, the company now owns nearly 106 million Class A and Class C shares of Alphabet, currently valued at approximately $36.6 billion.

The Alphabet stake has surpassed Berkshire’s $35.1 billion holding in Coca-Cola, but remains well below its positions in Apple and American Express, valued at approximately $69.7 billion and $51.9 billion, respectively.

Berkshire acquired approximately 48.1 million additional Alphabet shares during the quarter. About 60% of those shares were purchased directly from Alphabet through a $10 billion private placement announced in early June. This indicates that Berkshire bought the remaining approximately $7 billion worth of shares on the open market.

Alphabet was by far Berkshire’s largest stock purchase of the quarter. The company also substantially increased its investment in Delta Air Lines, expanding the position by 44%, or approximately $1.6 billion.

Berkshire now owns about 57.3 million Delta shares, valued at approximately $5.1 billion.