By Heekyong Yang and Joyce Lee

SEOUL (Reuters) -SK Hynix’s quarterly profit more than doubled on strong AI chip sales and stockpiling ahead of potential U.S. tariffs, but it warned that macroeconomic uncertainties could create demand volatility in the second half of the year.

The Nvidia (NASDAQ: NVDA ) supplier reported on Thursday a 7.4 trillion won ($5.19 billion) operating profit for the first quarter ended March, versus 2.9 trillion won a year earlier. That topped a 6.6 trillion won average forecast by LSEG SmartEstimate, which is weighted toward the more consistently accurate analysts.

Quarterly revenue for the South Korean firm jumped 42% to 17.6 trillion won.

In the first quarter, the "memory market ramped up faster than expected due to competition to develop AI systems and inventory accumulation demand", SK Hynix said in a statement, while cautioning about volatility stemming from "elevated macro uncertainties such as tariff policy" later in the year.

The company, however, said it expects spending by big tech firms on server chips to continue as they seek to capture early opportunities in the artificial intelligence (AI) market.

In smartphones, the advancement of AI features in new models is expected to drive replacement demand, boosting sales of high-performance mobile DRAM chips, it added.

SK Hynix has been leading a global race to meet explosive demand for high bandwidth memory (HBM) chips, a crucial component of AI chipsets made by the likes of Nvidia that help process vast amounts of data to train AI models.

The firm has been a main HBM chip supplier to Nvidia as its cross town rival Samsung Electronics (KS: 005930 ) has struggled to keep up in the race.

($1 = 1,426.4500 won)