SoftBank Group Corp. sold about $1.69 billion worth of its stake in Coupang Inc., the South Korean e-commerce giant whose stock surged and then tumbled after its initial public offering in March.

SoftBank sold 57 million shares at $29.685 on Sept. 14, the company said in a statement to the U.S. Securities and Exchange Commission. The Japanese company is still Coupang’s largest shareholder.

Masayoshi Son has stepped up sales of stakes in his portfolio of public companies in recent months, funneling the cash into more investments in technology startups. SoftBank sold roughly $14 billion worth of listed stocks last quarter, nearly triple the amount in the previous period. The selloff includes shares in some of Son’s biggest IPO hits like DoorDash Inc. and Chinese online property platform KE Holdings Inc.

Coupang’s March debut contributed $24.5 billion to SoftBank’s profit in that quarter, marking Son’s best return since Alibaba Group Holding Ltd.’s listing in 2014. But the shares have dropped about 16% below the $35 IPO price since, forcing SoftBank to book a $4.3 billion unrealized loss in the three months ended June.

SoftBank rose less than 1 percent  to 6,591 yen in Tokyo on Friday. Coupang closed at $29.41 in U.S. the previous day. (Bloomberg)