SK Hynix’s U.S. depositary receipts rose 12.8% on the first day, but South Korean shares fell as much as 8.2% today.

Listing in the U.S. has solved issues with trading access and liquidity, and the 12.8% first-day gain reflects institutional demand for a “HBM leader that can be traded directly”;
the drop in the Korean stock price indicates the market is starting to shift from the listing story to earnings verification.

Analysts believe investors are taking profits, while also worrying that HBM4 shipments have not increased at the scale previously expected in the second quarter.
SK Hynix’s share of HBM revenue in the first quarter was about 58%, ahead of Samsung and Micron, but its higher HBM exposure also makes it more sensitive to the progress of the next-generation products.

In addition, DRAM prices have recently risen, and Samsung—whose product mix is more balanced—may capture more relative upside.
SK Hynix’s long-term technical advantage has not been negated by a single day’s share price, but the market has entered a second phase:
no longer paying for listing scarcity, but waiting for HBM4 shipment volumes, gross margin, and capital returns.