The KOSPI and Kosdaq indexes are displayed on the electronic board at the dealing room of Hana Bank headquarters in Seoul, Thursday. KOSPI closed at 7,815.59, up 606.64 points, or 8.42 percent, from the previous session. Yonhap

The benchmark KOSPI staged a strong rebound Thursday, rising more than 8 percent in a single session on the back of a labor agreement at Samsung Electronics and Nvidia’s better-than-expected earnings results.

The index opened at 7,486.37, up 277.42 points, or 3.85 percent, and extended gains throughout the session to close at 7,815.59, up 606.64 points, or 8.42 percent.

It was the KOSPI’s strongest daily advance in 34 trading sessions since an 8.44 percent jump on April 1 and marked the index’s sixth-largest one-day gain on record.

The KOSPI had briefly topped the 8,000 mark intraday on May 15 before tumbling amid heightened market volatility. After two straight sessions of losses, the benchmark index rebounded sharply.