SK Hynix stock rebounds, but a new HBM4 risk is getting harder to ignore

SK Hynix stock rebounded on Tuesday as South Korean chip stocks recovered from early losses, but a shift in the next generation of high-bandwidth memory is creating a new question for investors.

The stock rose about 1.9% to 1.706 million won by 10:30 a.m. in Seoul, after falling roughly 9% over the past month. Foreign investors sold about 5.98 trillion won of SK Hynix shares during that period.

The weakness looks unusual against booming memory prices.

HBM export prices have reached a record $76.13 per unit, while conventional DRAM export prices jumped 24.3% in July. The concern is increasingly about who captures those profits.

Samsung is becoming a credible HBM4 alternative

SK Hynix built its leadership by moving early in HBM and becoming a critical supplier for AI accelerators, but Samsung Electronics is now making faster progress with HBM4, giving customers a stronger second source.

LS Securities estimates HBM4’s share of Samsung’s HBM shipments rose from about 5% in the first quarter to roughly 35% in the second. Its blended HBM yield also improved by more than five percentage points.

Jung Woo-sung, an analyst at LS Securities, told Seoul Economic Daily that the change “does not mean growth in the HBM market is slowing.” Instead, he described it as a normalisation of competition among suppliers.

That distinction matters as big technology customers generally prefer several qualified suppliers because it reduces supply risk and strengthens their bargaining position.

If Samsung can deliver HBM4 reliably at scale, SK Hynix may retain strong shipment growth while losing some pricing power that came with limited alternatives.

The bigger risk may be margins, not demand

That is already changing analyst assumptions.

LS Securities cut its SK Hynix target price by 27.3% to 2.4 million won from 3.3 million won while maintaining a buy rating. More importantly, it lowered its forecast for HBM operating margins next year to about 60% from roughly 80%.

The brokerage said HBM accounts for more than twice as much of SK Hynix’s intrinsic value as it does for Samsung under its estimates. That makes even modest changes in HBM profitability more important for SK Hynix’s valuation.

LS Securities also sees limits to further aggressive memory price increases. Supply should remain tight, but rising memory costs are taking a larger share of Big Tech server spending.

AI memory remains strong, but the premium may narrow

The broader industry backdrop remains firmly supportive.

Bank of America believes global DRAM revenue growth could exceed 80% in 2027 if AI demand keeps expanding while manufacturers remain disciplined on conventional memory capacity.

UBS has also forecast that SK Hynix will retain the largest share of HBM bit shipments this year at about 48%. But it expects Samsung to move ahead next year with roughly 41%, versus 39% for SK Hynix.

That would represent a more balanced competitive market, not the end of the AI memory boom.