Mizuho Financial Group (MFG) shares rose 3.5% on August 12. This gain extends a rally triggered by the company's July 30 first-quarter earnings report.

Mizuho beat analyst estimates and raised its full-year profit outlook. The firm also announced an expanded share buyback program to bolster investor confidence.

Market expectations for a Bank of Japan (BOJ) interest rate hike further lifted the stock. Analysts anticipate a potential rate increase as early as September.

A summary from the BOJ's July meeting showed growing momentum for a near-term hike. Higher rates typically improve net interest margins for Japanese banks like Mizuho.