SEOUL, South Korea (AP) — South Korean technology giant Samsung Electronics on Thursday reported a record operating profit of 89.5 trillion won ($62 billion) for the April-June period, a day after crosstown rival SK Hynix also reported record earnings, as the world’s two largest memory chipmakers continue to ride the global artificial intelligence boom.

Despite their soaring profits, the companies’ shares have fallen sharply this week in South Korea’s volatile stock market, where retail investors often drive sharp swings in share prices, as concerns grow over their plans to spend massively on increasing manufacturing capacity and the prospects of intensifying competition from China.

Samsung’s second-quarter operating profit was a more than 19-fold increase from a year earlier, and nearly all of it came from its semiconductor business, which benefited from rising chip prices driven by demand for AI servers and increased shipments of advanced high-bandwidth memory chips used to power AI applications. That outweighed an operating loss in its mobile, TV and home appliances division, partly due to higher component costs.

Samsung’s quarterly revenue of 171.5 trillion won ($119 billion) was also an all-time high. The company said it expects demand for its memory products to remain strong in the second half of the year, driven by continued expansion of AI infrastructure and broader adoption of agentic AI. Demand for server chips is expected to accelerate further, keeping the market undersupplied, it said in a statement.

Samsung’s report came a day after SK Hynix also reported a record second-quarter revenue of 60.5 trillion won ($42 billion). However, SK Hynx’s profit was still below the loftier market expectations and the company’s shares declined by more than 9% on Monday. Samsung’s share prices have also declined this week.

While Samsung and SK Hynix have embarked on major investments in semiconductor manufacturing facilities and data centers as South Korea expands its AI ambitions, some analysts say there are growing concerns about whether such massive spending will ultimately generate sufficient returns.

Shares of South Korean chipmakers have also been pressured by concerns over intensifying competition from China, with reports that a state-owned Chinese company had begun mass-producing domestically developed immersion deep-ultraviolet (DUV) lithography machines, a key technology for advanced chipmaking. Investor concerns were also heightened by the strong stock market debut of Chinese memory chipmaker ChangXin Memory Technologies, some analysts say.

Kim Tong-hyung, The Associated Press