Shares of South Korean chipmakers SK Hynix and Samsung Electronics surged to record highs on Friday, fueled by renewed optimism in the artificial intelligence (AI) sector and a wave of major tech investment deals.

After returning from a weeklong holiday, SK Hynix shares soared 10%, while Samsung Electronics climbed nearly 6%, reaching their highest levels on record, according to FactSet data.

The rally was driven by a series of AI-related developments, particularly news that OpenAI is planning to acquire a 10% stake in Advanced Micro Devices (AMD) as part of a strategic collaboration. Shares of AMD have jumped more than 40% this week, reflecting investor enthusiasm over the expanding partnership.

The surge also lifted Nvidia, whose shares gained 2.6% this week after CEO Jensen Huang told CNBC that AI demand continues to strengthen. Huang also confirmed Nvidia’s participation in funding Elon Musk’s AI startup, xAI, and expressed excitement about the company’s financing prospects, calling it “a major opportunity for the AI ecosystem.”

Investors see the recent flurry of deals as a sign of growing momentum in global AI chip demand, positioning South Korea’s largest semiconductor makers — Samsung and SK Hynix — as key beneficiaries in the supply chain. Both firms supply high-performance memory chips essential for AI model training, cloud computing, and data center expansion, giving them a critical role in the ongoing AI hardware race.

The rally underscores a broader market trend in which AI-linked semiconductor stocks continue to outperform, driven by accelerating adoption of AI technologies across industries and expanding strategic alliances among leading tech companies.