SK Hynix’s stay in the trillion-dollar club lasted about 10 days. The South Korean memory chipmaker, which crossed the $1 trillion market capitalization threshold on May 27, has seen its valuation slide to approximately $943 billion following a sharp single-session selloff.

The stock dropped nearly 10% in one day. The company’s shares have risen more than 800% over the past year.

From milestone to pullback in record time

SK Hynix became the third Asian company to reach the $1 trillion valuation when its shares surged as much as 11% on May 27. That put it in rare company alongside Samsung Electronics, which crossed the mark on May 6, and Micron Technology, which hit the threshold just one day earlier on May 26.

By early June, SK Hynix’s share price gave back a significant chunk of those gains. The roughly $57 billion evaporation in market value happened fast enough to remind investors that memory chip stocks remain cyclical.

The AI-powered rise that got SK Hynix here

SK Hynix has positioned itself as the dominant supplier of High Bandwidth Memory, or HBM, which is the specialized DRAM that powers AI accelerators and data center GPUs. The company holds over 57% market share in the HBM segment.

SK Hynix reported record results for Q1 2026, posting operating margins of approximately 72%. The extraordinary profitability stems from aggressive price increases across HBM, DRAM, and NAND product lines, all buoyed by insatiable demand from hyperscale data center operators racing to build out AI infrastructure.

What this means for investors

On the bullish side, SK Hynix still controls more than half the HBM market, its margins remain historically elevated, and the structural demand drivers show no signs of slowing down.

On the cautious side, memory chips are notoriously cyclical. An operating margin of 72% is extraordinary, but it also implies that prices are well above long-term equilibrium. When Samsung and other competitors bring additional HBM capacity online, pricing pressure is almost inevitable.

Traders should also watch broader semiconductor sentiment closely. Memory stocks as a group are sensitive to any signals about AI spending growth rates, customer inventory levels, and pricing trends in the DRAM and NAND markets.