SK hynix shattered its quarterly earnings record in the second quarter, just three months after setting its previous high.

Still, its shares extended losses Wednesday as the record results failed to meet elevated market expectations, adding to concerns that the artificial intelligence (AI) infrastructure investment boom may be losing momentum — a claim the Korean chipmaker dismissed.

During its earnings call, SK hynix said its second-quarter operating profit soared 557.2 percent from a year earlier to 60.54 trillion won ($41.6 billion). Revenue for the quarter reached 79.32 trillion won, up 256.8 percent year-on-year.

Both revenue and operating profit set new records, surpassing the previous highs of 52.58 trillion won in revenue and 37.6 trillion won in operating profit. Its operating margin reached 76 percent.

However, the results fell short of brokerages' consensus estimates of 83.94 trillion won in revenue and 63.99 trillion won in operating profit.

The company attributed the strong performance to continued demand driven by expanding AI infrastructure investment, with higher prices for high-performance AI server memories lifting earnings. Its first-half revenue exceeded 100 trillion won for the first time.

"Prices for both DRAM and NAND posted sharp increases from the previous quarter," SK hynix said. "We achieved record profitability by expanding sales of high-value-added products, including high-bandwidth memory (HBM), AI server DRAM and enterprise solid-state drives."

During the earnings call, the company said it is receiving growing supply requests from Big Tech companies expanding AI infrastructure investment. Based on the demand outlook, it is engaging customers on multiyear contracts and concluded negotiations on long-term agreements (LTAs) with around 10 customers, including key clients.

“The standard LTA term is typically five years, but the specific terms may vary depending on the customer and the product," the company said. "Rather than adopting a single pricing model, we are discussing various pricing structures with customers to help address price volatility."

To reduce earnings volatility tied to the memory cycle, SK hynix and other memory chipmakers have been expanding LTAs. Despite those efforts, investors remain haunted by the worry that a slowdown in AI infrastructure investment could eventually lead to an oversupply of memory chips.

SK hynix shares fell 9.48 percent before noon Wednesday, following a 14.65 percent drop in the previous session. Excluding Wednesday's decline, the stock has suffered four single-day losses of more than 10 percent this month.

“We believe the industry is moving into a stage of improving utilization and accelerating the monetization of the infrastructure that has already been built, rather than entering a phase of reduced AI investment," the company said. "As our capacity expansion will remain flexible, we believe the likelihood of mid- to long-term investment immediately leading to an oversupply is limited."

The company said it is considering additional shareholder return measures and plans to disclose them to the market later this year. It also said that its American depositary receipts listed in the United States can be converted into common shares beginning Thursday.

The company began mass shipments of HBM4 in the second quarter and plans to significantly ramp up production in the second half. It has also completed the sample deliveries of the next-generation HBM4E in the first half and plans to start mass production next year.

SK hynix said it expects overall shipment growth in the second half to outpace that of the first half, driven by a significant increase in HBM4 shipments and higher shipments of conventional DRAM based on its sixth-generation 10-nanometer-class process.

“A higher proportion of HBM4 and other high-value-added products in our sales mix will contribute positively," the company said. "As a result, we expect our earnings momentum to strengthen further in the second half, supported by both higher shipment volumes and rising average selling prices."

Regarding its NAND business, the company said its 321-layer NAND products already account for the largest share of its total production, and it plans to expand their share to about 50 percent of its domestic production capacity by the end of the year.

To meet growing demand, SK hynix said it has accelerated the production schedule for its M15X fab while investing to rapidly expand capacity.

It said its mid- to long-term investment plans, including the recently announced P&T7 advanced packaging facility, the M17 NAND production base and the new semiconductor cluster, will be carried out in phases based on customer demand and investment efficiency.