Samsung Electronics (SSNLF, Financials), the South Korean technology company known for memory chips, smartphones, displays and consumer electronics, reported record preliminary second-quarter profit, but investors were not in a celebrating mood.

The company's operating profit reached 89.4 trillion won, or about $58.4 billion, up from 57.2 trillion won in the previous quarter. Compared with a year earlier, profit jumped more than 1,800%.

Revenue came in at 171 trillion won, up from 133.9 trillion won in the first quarter and more than double the year-earlier level.

Still, Samsung shares closed nearly 7% lower. The problem is expectations. Investors had already spent months pricing in a strong memory-chip cycle, and the record numbers did little to ease concerns about whether AI infrastructure spending can keep growing at its current pace.

Higher employee bonuses and Samsung's plans for large new semiconductor plants in South Korea are also raising questions about future costs.

For investors, the quarter shows AI demand is still supporting memory prices. The bigger question now is how long that demand can stay this strong as customers face higher chip prices and rising infrastructure bills.