SK hynix (SK hynix (SKHY)) is having a moment. The memory-chip maker's U.S.-listed shares jumped more than 6% in Tuesday's premarket session, as investors kept piling into the stock after its blockbuster Nasdaq debut. Nasdaq futures were up 0.59%, while the S&P 500 futures slipped 0.10% — so SK hynix is clearly outpacing the broader market.

The gains build on a strong first few days of trading. The company completed a $26.5 billion U.S. listing, with American depositary receipts (ADRs) priced at $149. On the first day of regular trading, the stock opened about 14% higher at $170 and finished the session up 12.76% at $168.01. It added another 2.43% in after-hours trading. Market commentary suggested the ADRs priced at roughly a 3% premium to the Seoul-listed shares, a level seen as reasonable given strong institutional demand.

But while U.S. investors are cheering, the story in South Korea is different. SK hynix's Seoul-listed shares fell 12.89% to 1.89 million South Korean won. An analyst cited by Reuters attributed the decline to profit-taking and a "correctional period" driven by the additional share issuance and valuation uncertainty. So the same event — a U.S. listing — is creating a divergence: American buyers see opportunity, while Korean holders are cashing out.

The enthusiasm for the U.S.-listed shares is largely about AI. SK hynix is widely viewed as a leader in high-bandwidth memory (HBM), a critical technology used in AI accelerators and advanced computing systems. That positioning has helped strengthen investor interest in the new ADRs, especially compared to rivals like Micron Technology (Micron Technology (MU)).

The strong reception for SK hynix's Nasdaq debut has also fueled speculation that Samsung Electronics (Samsung Electronics (SSNLF)) could pursue a U.S. listing. Bloomberg reported Tuesday that Samsung has begun preliminary discussions with banks about a potential U.S. initial public offering or ADR listing, although the company has not made a final decision. Later Tuesday, Reuters reported that Samsung said it is not reviewing the possibility of issuing American depositary receipts, pushing back on the Bloomberg report. So it's unclear whether Samsung will follow SK hynix's path, but the idea is certainly in the air.

As for Tuesday's price action: SK hynix shares were up 6.56% at $162.34 during premarket trading, according to market data. The stock is still trading below its opening day high of $170, but the momentum suggests investors are betting that the AI memory story has legs — and that SK hynix is the best way to play it.