Shares of Jiayin Group Inc. (NASDAQ: JFIN) plummeted 6.39% in pre-market trading on Wednesday, despite reporting strong second-quarter revenue growth. The Chinese fintech company's stock decline comes as investors appear concerned about rising costs and expenses.

Jiayin Group announced its Q2 2025 unaudited financial results, revealing a 27.8% year-over-year increase in net revenue to RMB1,886.2 million (US$263.3 million). The company's net income also saw a significant rise of 117.8% to RMB519.1 million (US$72.5 million). However, the positive top-line and bottom-line growth was overshadowed by a sharp increase in operating expenses, particularly in general and administrative costs, which surged 70% from the previous year.

Adding to investor concerns, Jiayin Group announced an adjustment to its existing share repurchase plan. The Board approved an increase in the aggregate value of ordinary shares authorized for repurchase to US$80 million through June 12, 2026. While share buybacks can be seen as a positive sign, the timing of this announcement alongside rising costs may have contributed to the stock's significant drop in pre-market trading.