According to an article in Bloomberg, China’s $1.2 trillion sovereign wealth fund has lost its quant trading team leader. Zhang Rong’s resignation from China Investment Corp.’s public equities department in December is just the latest from the firm. Wu Jian’an resigned his position as director and team leader in the private equity department as well.

The two directors join the more than 20 team leaders and managing directors who have left CIC in recent years. That mass exodus drove CIC to create a leadership group for upper-management recruitment two years ago to refill their talent pool. The group has recruited a handful of people, and CIC told Bloomberg that personnel changes are “a normal phenomenon.”

CIC has been working toward boosting its in-house investing capabilities and expanding investments that will improve the firm’s long-term results amid volatile markets. The proprietary quant trading platform was set up in 2015, and saw high returns for several self-managed portfolios that year. It’s also been expanding private equity co-investments as part of its approach of raising the amount of direct and alternative assets to 50% by the end of this year.

But the firm’s attractiveness as an employer has lost its luster as competitors outdo them on compensation and restrictions tighten, the article contends. In addition to Zhang Rong and Wu Jian’an, at least five other employees left the company last year.