The South Korean won strengthened to a more than two-month high against the dollar on July 23 as the economy posted better-than-expected growth in the second quarter.
According to the Bank of Korea, real GDP rose 0.6 percent in the April-June period from the previous quarter, exceeding the central bank's May forecast of 0.2 percent growth.
The benchmark KOSPI closed up 299.19 points, or 4.4 percent, at 7,096.89. Foreign investors bought a net 2.1 trillion won worth of local stocks, with semiconductors leading the gains.
The won was quoted at 1,466.8 won per dollar at 3:30 p.m., up 13.3 won from the previous session. The won-yen rate fell below 900 won per 100 yen for the first time in about 20 months.
Samsung Electronics rose 3.65 percent and SK hynix gained 4.85 percent. Alphabet's cloud revenue jumped 82 percent year-on-year, boosting expectations for continued memory chip demand.