Samsung stock rebounds, SK Hynix sinks: here’s why Korea's AI trade is diverging

Samsung Electronics shares rebounded sharply on Tuesday while SK Hynix stayed in the red, splitting South Korea’s two biggest memory-chip makers.

Samsung was up 3.26% by 11:20 AM KST after opening lower, while SK Hynix fell 1.90%. The KOSPI reversed an opening decline of 0.95% to gain 0.53%, helped by 1.29 trillion won of net foreign buying.

The divergence suggests investors may be starting to favour Samsung’s broader memory recovery over SK Hynix’s more concentrated exposure to high-bandwidth memory.

Samsung stock's comeback is becoming harder to dismiss

Samsung stock's rebound comes as its memory business regains ground lost early in the AI boom.

Counterpoint Research estimates Samsung reclaimed the top position in global DRAM revenue in the second quarter with a 39% share, returning to levels last seen in 2024. SK Hynix, which led a year earlier, fell to 26%.

Counterpoint senior analyst Jeongku Choi called Samsung’s performance an “exemplary turnaround”, saying robust conventional DRAM demand, price increases and a growing HBM share were strengthening earnings.

That mix matters, as Samsung no longer needs HBM alone to carry the investment case.

Conventional DRAM prices have risen sharply as AI servers and CPUs consume more memory, giving the company a wider earnings engine while its HBM position improves.

Shareholder returns could add a catalyst. KB Securities head of research Kim Dong-won said, according to Financial News, that large-scale capital returns could drive a revaluation.

The brokerage kept a Buy rating and 600,000 won target, while forecasting third-quarter operating profit of 112 trillion won.

SK Hynix stock's AI strength is also creating volatility

SK Hynix’s weakness does not mean its AI-memory leadership has disappeared.

Counterpoint said the company’s DRAM revenue still rose 214% year on year. But its market share declined as Samsung and Micron grew faster.

Research director MS Hwang said SK Hynix has a larger proportion of shipments and revenue coming from HBM than rivals, leaving it more exposed when average HBM prices fell.

Long-term agreements signed earlier can also leave contracted prices below rapidly rising market prices.

That is the trade-off investors are confronting. SK Hynix’s concentrated HBM exposure delivered exceptional leverage to the AI boom, but it can also produce sharper swings when investors question pricing or the durability of spending.

The case remains strong. HBM4 shipments are increasing as Nvidia Vera Rubin and AMD Instinct MI455X systems ramp.

William Blair analyst Sebastien Naji called SK Hynix the “memory leader for the AI era,” according to Barron.

AI-memory trade may be rotating, not ending

The wider memory backdrop remains constructive, but investors may be becoming more selective.

Morgan Stanley said the sharpest part of the recent memory-stock correction appears to be over and described current valuations as a tactical re-entry opportunity.

It sees strong demand for high-value products such as HBM as AI data-centre investment expands.

The bank also warned that memory-price increases could slow from the fourth quarter as supply and inventories rise, limiting further earnings upgrades.

That makes the difference between Samsung and SK Hynix increasingly important.

Samsung offers exposure to conventional DRAM pricing, improving HBM competitiveness and larger shareholder returns.

SK Hynix offers the purer bet on premium HBM and the Nvidia-led AI infrastructure cycle.