After a near 10% decline over two sessions, South Korea's stock market rebounded sharply on Friday, underscoring the sensitivity of investor sentiment as questions arise about the sustainability of the global artificial intelligence boom.

The Kospi index surged as much as 5.5% during the session, with shares of Samsung Electronics Co Ltd and SK Hynix Inc both skyrocketing. The sharp rise in KOSPI futures even prompted a brief suspension of program buying by the Korea Exchange. While foreign and retail investors were net sellers of index constituents, domestic institutional funds increased their holdings.

The market has been dominated this week by shifting sentiment in AI-related trades. Against a backdrop where shares of the two major local chipmakers had surged as much as twofold this year, the overheated rally has left investors highly sensitive to news flow. The latest catalyst was a report that Anthropic PBC is in talks with Samsung to jointly develop a custom AI chip, boosting the production outlook for the Korean chipmaker. Furthermore, the market holds high expectations for Samsung's preliminary earnings results scheduled for release next Tuesday.

"The Anthropic-Samsung project is in its early stages, so the impact on earnings in the short term is limited, but it holds positive strategic significance," said Jung In Yun, CEO of Fibonacci Asset Management Global. "It solidifies Samsung's position in the AI chip space and the importance of Asia in the AI semiconductor supply chain."