What moves xyz:SKHX when Seoul is closed
The SK hynix market on Hyperliquid is xyz:SKHX (the app labels it SKHYNIX), listed by trade.xyz on the xyz HIP-3 dex. It is a perpetual future on 1 SK hynix common share (KRX: 000660), its KRW price converted to USD at the live USD/KRW rate. That makes it unusual among Hyperliquid stock markets: the reference price is set in Seoul, in won, by a market that closes every evening and every weekend, while the perp trades every hour of every day in dollars. Most of what surprises SK hynix traders here comes from that mismatch, so this section goes through it piece by piece.
One share in Seoul, priced in dollars
The oracle takes executable KRX quotes from institutional data providers and divides them by a real-time USD/KRW rate (Pyth feed). The perp therefore moves when the share moves and also when the won moves. A day on which SK hynix closes flat in won can still show a gain or a loss on xyz:SKHX if USD/KRW changed, and a Korean investor who thinks in won sees a third layer on top: the rate at which the USDC margin was bought. A tracker that converts the perp back into won with a different rate, for example a USDT price on a Korean exchange, shows a different won figure for the same dollar print.
Two external windows, and the hours in between
External pricing runs in two blocks: the main session from 9:01 AM to 3:20 PM KST and an after-hours block from 4:05 to 8:00 PM KST. Note the first one ends before the KRX regular session does (KRX: 9:00 AM to 3:30 PM KST), so the last minutes of the Seoul session and the closing-price period are covered by the internal price, not by Seoul. Everything else on a weekday, 3:20-4:05 PM and 8:00 PM-9:01 AM KST, is internal as well. The docs add one more trigger, which applies inside the after-hours block too: if external datapoints stop for more than 15 seconds, the oracle switches to internal pricing even inside an external window.
There is no pre-market window any more. When we read the Korea page on October 4, 2026 it listed a pre-market session of 8:10 to 8:50 AM KST; on October 19, 2026 the page listed only the main and after-hours sessions, and the changelog shows the pre-market row replaced by a dash.
The July 28 pre-market print
The pre-market window is where the best-known SK hynix event on Hyperliquid happened. At July 27, 2026, 23:01 UTC, which was 8:01 AM KST on July 28, 2026, a single executed trade on the main Korean pre-market venue was relayed by several data providers, and the mark price fell from $1,127.90 to $917.25, −18.7% in one update. Leveraged longs were liquidated at that print. trade.xyz said the oracle had worked as designed and still covered the liquidation losses, measured against a reference price of $1,115.50: amounts under 10,000 USDC were credited in full, larger ones got 9,999 USDC first and the rest after extra checks. It called this a one-time decision, not a promise for the future. The lesson for a position here is mechanical: a liquidation price is checked against whatever the oracle prints, and a thin session can print far from the last trade you saw.
Korean holidays: two measured closures
On Korean exchange holidays the market stays open on its internal price, inside bounds of ±10% with 1 re-anchor per direction, so roughly +21% to −19% from the last external price across one closure. Two closures this autumn show what that looks like in practice. Over Chuseok (internal pricing from September 23, 2026, 20:00 KST to September 28, 08:10 KST) the hourly low was −4.3% from the last external price and the final internal hour was −0.9%; the first main-session hour then closed −3%, while the KRX close moved −5% across the break. Over Hangeul Day (October 8, 2026, 20:00 KST to October 12, 08:00 KST) the low was −5.2%, the last internal hour −1.5% and the first main-session hour −3.2%. Between the last internal hour and the close of the first main-session hour came the pre-market window then in force (8:10 to 8:50 AM KST) and an hour of KRX trading, so that last step is not a single reopening gap. Two closures are not a rule. The rest of 2026 has December 25 and December 31 left on the Korean list.
SKHX is not 10 SKHY
trade.xyz also lists xyz:SKHY, the SK hynix ADS on Nasdaq; 10 ADS make one common share. It is priced from US trading, 24/5, from Sunday 8:05 PM to Friday 8:00 PM ET, so during the Korean night it has an external price while xyz:SKHX runs on its internal oracle. The two are not interchangeable at the stated ratio: on October 20, 2026, in the same API response, 10 SKHY were priced 50.6% above one SKHX. That gap is not a quirk of the perps: on their October 19, 2026 closes, 10 ADS on Nasdaq were worth 49.2% more than one KRX share converted at USD/KRW, so the listed ADS itself trades at a premium to the Seoul share. Each market has its own order book, funding rate and liquidation price, and the gap between them moves on its own. The same-underlying table below lists both side by side.
Liquidity, margin and the weekend
xyz:SKHX is the busiest market on the xyz dex: it ranked first by 24-hour volume among the live xyz markets on October 19, 2026 and again on October 20, 2026 ($356.7M in the 24 hours to the second check). The weekend is much quieter. Over the 28 days to October 4, 2026, an average Saturday or Sunday traded about 25% of an average weekday. It is also one of the few xyz stock markets that allows cross margin, at up to 10x in one tier. At 10x the maintenance margin is 5%, so an isolated long at full leverage is about 5.3% from liquidation: less than one 10% bound step, which is the distance the price can travel during a single Korean holiday before re-anchoring.