KRX vs NXT vs SOR: Why One Korean Stock Has Three Prices
Since an alternative trading system launched, a single Korean stock effectively has three prices. Here's what separates them — trading hours, order types, fees, and what it means for the numbers you see on screen.
00 Why there isn't just one price anymore
For decades Korea had exactly one stock exchange. If you wanted to buy Samsung Electronics, you went through the Korea Exchange (KRX), and "the price of Samsung Electronics" was a single number no matter who you asked.
That changed in 2025 when Nextrade (NXT), Korea's first alternative trading system, opened for business. The same stock now trades in two venues, and the two order books move independently. At any given moment KRX might show 100,000 KRW while NXT shows 100,100 KRW.
To keep investors from having to decide which venue is better on every single order, there's SOR. The three terms sit at different levels, which is the first thing to get straight.
- KRX — Korea Exchange. The incumbent, primary exchange
- NXT — Nextrade. An alternative trading system (ATS) launched in 2025
- SOR — Not a venue at all, but a routing feature (Smart Order Routing) that automatically picks the better of the two. Your broker provides it
In short: KRX and NXT are places; SOR is the thing that chooses between them. Miss that distinction and everything below stays confusing.
01 Trading hours — from 6.5 hours to 12
KRX 09:00–15:30 (plus batched off-hours sessions) · NXT 08:00–20:00, all times KST
This is the difference you feel most. The KRX regular session runs 09:00–15:30 — six and a half hours. NXT runs 08:00 to 20:00, twelve hours. That's why it's now possible to trade Korean stocks in the evening.
| Session | Hours | Mechanism |
|---|---|---|
| Pre-market | 08:00–08:50 | Continuous trading |
| Halt | 08:50–09:00:30 | KRX forms the opening auction price |
| Main market | 09:00:30–15:20 | Continuous trading |
| Halt | 15:20–15:30 | KRX forms the closing auction price |
| After-market, phase 1 | 15:30–15:40 | Single-price auction |
| After-market, phase 2 | 15:40–20:00 | Continuous trading |
There's a deliberate design choice here worth noting. The official opening and closing prices are still set exclusively by KRX. NXT stops trading entirely during those two windows (08:50–09:00:30 and 15:20–15:30). If two competing official closing prices existed, index calculation and next-day reference pricing would break — so the overlap is avoided on purpose.
02 How far do the rules actually differ?
Order types · fees · volatility interruption · circuit breakers · short selling
It isn't only the hours. Same stock, meaningfully different rulebook.
One thing to know up front: not every stock trades on NXT. The list grew to around 800 names after launch, then settled back to roughly 650 — about 360 from KOSPI (Korea's main board) and 290 from KOSDAQ (its growth market). The cap exists because Korean law limits how much total volume an alternative trading system may handle, so the universe can't expand indefinitely. Excluded names are unavailable across all NXT sessions and trade on KRX only.
| Item | KRX | NXT |
|---|---|---|
| Hours (KST) | 09:00–15:30 (+ off-hours) | 08:00–20:00 |
| Tradable universe | All listed stocks | ~650 names (index membership, market cap, turnover) |
| Market orders | Available | No plain market order — IOC/FOK only, main market |
| Midpoint & stop-limit | Not offered | Supported (main market) |
| Execution fee | 0.0023% | Maker 0.0013% / taker 0.0018% |
| Transaction tax | 0.20% (KOSPI & KOSDAQ) | Identical (0.20%) |
| Daily price limit | ±30% from prior close | Identical (±30%) |
| Static VI | Yes | No |
| Dynamic VI trigger | 2-minute auction | 2-minute halt |
| Circuit breakers | 3 stages | 2 stages (30 min each, then close) |
| Short selling | Permitted per regulation | Banned in pre- and after-market |
Two rows in that table are Korea-specific and worth unpacking if you're coming from US or European markets.
- Daily price limits. A Korean stock cannot move more than ±30% from the previous day's close. There is no US equivalent, and it applies identically on NXT — calculated from the same KRX reference price.
- Volatility Interruption (VI) is a per-stock cooling-off trigger, not a market-wide halt. A dynamic VI fires when a single print jumps too far from the immediately preceding price; a static VI fires when price strays too far from the day's reference price. KRX responds by flipping that stock into a brief auction. NXT instead halts it for two minutes, and has no static VI at all.
Fees: a maker-taker model
NXT charges differently depending on whether you post liquidity (maker) or take it (taker). Makers pay less. Either way it undercuts KRX's 0.0023%, so on execution fees alone NXT runs roughly 20–40% cheaper.
That said, this is the fee the exchange collects. As a share of what you actually pay it's tiny — brokerage commission and tax dominate.
Tax is the same either way
NXT is a licensed multilateral trading facility under Korean capital markets law, so trades there count as on-exchange trades. That means the securities transaction tax is identical to KRX (0.20% for both KOSPI and KOSDAQ as of 2026, charged on sales only). Pre-market and after-market are no different. And since tax dwarfs the exchange execution fee, which venue your order reaches doesn't meaningfully move your total cost.
No plain market orders
A more consequential limitation than it sounds. NXT has no "fill at any price" market order. In the main market you can only use IOC (fill what you can immediately, cancel the rest) or FOK (fill entirely and immediately, or cancel entirely). If you habitually use market orders to get filled fast, that approach doesn't carry over to NXT.
03 Where are your orders going right now?
By this point the obvious question is: which venue am I actually trading on? The short answer is that most people are already routing through SOR. There's nothing to sign up for — brokers enable it by default. If you've never touched the setting, your orders are already being sent to whichever venue looks better.
Both desktop and mobile platforms display whether a given order is going to SOR, KRX, or NXT. You can also turn SOR off and pin a specific venue. Menu locations vary by broker and app version, so it's worth opening your own order window once just to see how it's labeled.
04 What foreign investors need to know
Nothing is closed off on the regulatory side. Foreign investors can trade on NXT the same way they trade on KRX, and there's no separate registration for NXT access — the existing foreign investment process applies unchanged.
The real gate is a practical one: whether your broker is an NXT member. Early on, foreign brokerages were slow to complete the systems work, and foreign participation on NXT sat at just 0.4% of volume. That has shifted substantially. Morgan Stanley and Merrill Lynch joined as members, Interactive Brokers began supporting NXT trading, and by February 2026 foreign investors accounted for roughly 13% of NXT volume. Nextrade publishes the current member list on its official site.
- Does your broker support NXT? If not, your orders only reach KRX and you won't see combined quotes either
- Does it apply SOR? With two venues live, no SOR means choosing a venue manually every time. Interactive Brokers, for instance, applies SOR across KRX and NXT and routes to whichever shows the better price
The extended hours matter more if you're outside Korea. Korea Standard Time is UTC+9 all year — Korea does not observe daylight saving, so the conversion never shifts on the Korean side. That puts the NXT after-market (15:30–20:00 KST) at 06:30–11:00 UTC: a morning window for European-hours investors, who can work the back half of the Korean session inside their own working day. For the US East Coast the same window falls overnight (01:30–06:00 EST), so the practical benefit is thinner.
05 Measured: same stock, same day, very different numbers
SK Hynix (000660), 2026-07-24 daily bar, queried three ways
Numbers make this clearer than prose. Here is one stock's daily bar for a single session, pulled three ways.
| Venue | Open | High | Low | Close | Volume |
|---|---|---|---|---|---|
| KRX only | 1,894,000 | 1,894,000 | 1,752,000 | 1,759,000 | 4,935,624 |
| NXT only | 1,900,000 | 1,909,000 | 1,756,000 | 1,781,000 | 2,978,820 |
| SOR (combined) | 1,900,000 | 1,909,000 | 1,752,000 | 1,781,000 | 7,914,444 |
The closing prices differ by 22,000 KRW, about 1.25%. Volume diverges much further — KRX alone shows only 62% of the combined figure.
Read the table closely and you can see exactly how the combined bar is assembled.
- Volume: 4,935,624 + 2,978,820 = 7,914,444. An exact sum of the two venues.
- Low: the lower of KRX's 1,752,000 and NXT's 1,756,000 becomes the combined low.
- High: likewise, the higher of the two (1,909,000) becomes the combined high.
- Open and close: both match NXT. Since NXT opens earlier and closes later, the day's first and last prints both happen there.
In other words, the combined daily bar is the entire 08:00–20:00 window compressed into a single candle.
06 The catch: "close" stops meaning what you think
Which leads to the consequence. On combined data, a daily bar's open and close are not the open and close you have in mind.
| Source | "Open" is | "Close" is |
|---|---|---|
| KRX only | 09:00 opening auction | 15:30 closing auction |
| SOR (combined) | 08:00 first pre-market print | 20:00 last after-market print |
So the same stock on the same day shows a different percentage change. SK Hynix closed the previous session at 1,919,000 KRW. Plug each venue's close into that and the gap opens up.
| Source | Close | Change | % change |
|---|---|---|---|
| KRX only | 1,759,000 | -160,000 | -8.34% |
| SOR (combined) | 1,781,000 | -138,000 | -7.19% |
A 1.15 percentage point spread. One stock, one session — and depending on which quote basis you're looking at, it reads as either -8.3% or -7.2%.
So which one is the "official" close?
The official close is the KRX 15:30 closing price. Index calculation, next-day reference pricing, and daily price limits all use that number, and it's the figure quoted when the market is reported as finishing up or down for the day.
That doesn't make the combined price wrong. It reports something else — the last price at which the stock actually traded before 20:00. The two numbers simply describe different things. If you want to see what happened after 15:30, the combined basis is what you need.
Volume diverges even more
As above, KRX alone reveals only about 62% of real liquidity. Any judgment along the lines of "volume spiked today" depends on which basis you happen to be looking at.
07 Takeaways
- KRX and NXT are venues; SOR is a feature. SOR isn't an exchange — it's a broker service that routes your order to whichever of the two is better.
- NXT runs 08:00–20:00 KST but halts during the two windows that form the official opening and closing prices — those still come from KRX alone.
- The rules differ more than you'd expect. No plain market orders, no static VI, different circuit breaker stages, and short selling is banned in the pre- and after-market.
- Tax is identical in either venue. NXT trades count as on-exchange trades, so there's no transaction tax difference.
- Foreign investors face no regulatory barrier. The question is practical — whether your broker supports NXT and applies SOR.
- On combined data, "open" and "close" are the 08:00 and 20:00 prints. In the measurement above that shifted the close by 1.25%, the daily percentage change by 1.15pp, and volume by 38%. The official close remains the KRX 15:30 price, which is what indices, reference prices and price limits are built on.
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