South Korean shares jumped nearly 5% at at Monday's close, hitting a five-week high, as OpenAI launched its next‑generation AI model, which lifted demand for AI‑related and semiconductor stocks.

The Korea Composite Stock Price Index, or Kospi, increased by 308.18 points, or 4.6%, to close at 6,995.39. The Kosdaq also rose by 8.69 points, or 1.1%, to close at 822.19.

Shares of market bigwigs Samsung Electronics (KRX:005930) and SK Hynix (KRX:000660) added 6% and over 8% at market close.

In corporate news, CS Wind (KRX:112610) secured a contract worth roughly 151 billion won with Vestas American Wind Technology on Friday for the supply of wind turbine structures. The order is valid until July 2, 2027.

Shares of CS Wind gained 4% at market close.

LG Electronics (KRX:066570) denied media reports that its U.S. unit Bear Robotics is seeking a Nasdaq listing, saying no decision has been made and that it will issue a follow‑up disclosure once details are finalised or within one month.

LG shares jumped more than 6% at the close.