Key Takeaways
- Korea’s order-type menu is longer than a US or European desk expects. Two of its types—the Immediately Executable Limit Order and the conditional limit-to-market-on-close order—don’t map cleanly onto anything most foreign brokerage platforms expose by that name.
- The continuous session runs on price priority, then time priority, the same logic as most developed markets. The call auction that opens and closes each day doesn’t use time priority at all—it settles ties by whether the order is a customer order or a member firm’s own, then by size.
- Tick size widens in steps as a share price rises, on one unified ladder since a 2023 reform—KOSPI, KOSDAQ, and KONEX all use the same table now, which wasn’t true before.
- A plain market order doesn’t exist everywhere on this market. It’s barred from the closing auction and from Nextrade’s (NXT) main session outright, which accepts only IOC/FOK-qualified market-type orders.
- Nextrade, the alternative venue running alongside KRX since March 4, 2025, is a second venue with its own mechanics, not a mirror of KRX’s order book. It offers two order types KRX doesn’t (mid-point, stop-limit), and its Volatility Interruption is resolved as a flat trading halt through September 13, 2026—a rule change effective September 14, 2026, aligns it closely with KRX’s two-minute call-auction resolution.
- This is the deep version of one section of the pillar piece, How Korea’s Trading Day Works, which sets order tactics aside on purpose. It doesn’t tell you which order type to use. It tells you what each one actually does.
Contents
- What governs a resting order
- The order-type menu
- Tick size: one ladder, since 2023
- Trading unit: one share, with one exception
- NXT: a second venue, not a second copy
- Four traps investors keep falling into
- FAQ
1. What governs a resting order?
The companion pillar, How Korea’s Trading Day Works, walks a single order through venues, sessions, halts, and settlement. It stops short of the order-type menu itself and flags that as a separate question. This piece is that question.
Start with the rule that decides who gets filled first. In the regular session (09:00–15:30), matching runs as a continuous auction. A new or modified order executes immediately against the resting book. The rule is price priority, then time priority: the better price wins, and among equal prices, the order that arrived first wins. That’s the same logic used on most developed exchanges. It’s the one part of this system that won’t surprise anyone.
The Korea Exchange’s own trading guide adds one qualifier worth noting. Price/time priority is “not applied to issues with low liquidity.” In practice, an illiquid or newly designated issue is moved out of continuous matching entirely. It trades instead in a periodic single-price auction—typically a call every 10 minutes during the regular session. Issues under a delisting-review or short-term-overheating designation get a wider, 30-minute call. If you trade a thin name, expect it to behave like the call-auction sessions described next, not like a normal continuously matched stock.
The opening and closing sessions run differently. They use a periodic, single-price call auction, not continuous matching. Orders accumulate for a window. Then they clear at whichever single price fills the most volume, all at once, rather than trading continuously as they arrive. Price priority still governs which orders clear. But time priority does not apply inside the auction window—every order that arrived during the window is treated as simultaneous. The tie-break instead runs customer orders ahead of a member firm’s own proprietary orders at the same price. After that, a larger quantity beats a smaller one. It’s a different hierarchy from the continuous session, not merely a suspension of the one described above.
2. The order-type menu
Korea’s exchanges publish a longer order-type list than most foreign brokerage front-ends expose. The part that catches people: not every type is legal in every session.
Limit Order. The baseline. Legal in every session this market runs—opening auction, continuous session, closing auction, the pre- and after-hours closing-price sessions, the after-hours session in both its forms (see the dated note at the end of this section), and block trades.
Market Order. Priced at whatever the book offers; only the quantity is fixed. Legal in the opening auction and the continuous session. Not legal in the closing auction, either the closing-price session, any form of the after-hours session, or a block/basket trade. A trader used to placing a market order into a close needs a different tool here—see the next entry.
Limit-to-Market-on-Close Order (jogeonbu-jijeongga, sometimes rendered “conditional limit order”). A limit order with an automatic fallback. If it sits unfilled through the end of continuous trading, the exchange resubmits it as a market order into the closing single-price auction. It exists to solve the problem the previous paragraph creates: a way to say “fill me at whatever the close turns out to be,” without placing an outright market order, which the closing auction won’t accept.
Immediately Executable Limit Order (choe-yuri-jijeongga) and Best Limit Order (choe-useon-jijeongga). Both names are KRX’s own English terms, from its trading guide. Both are legal only in the continuous session. Both are priced automatically by the exchange, not typed in by the trader. The first price is a buy at the best available ask, a sell at the best bid, and the instant it’s submitted, a marketable limit order, in that sense. Whatever quantity is sitting there fills immediately. Any unfilled remainder is not cancelled: it converts into a resting limit order at that same assigned price, queued like any ordinary limit order rather than disappearing. The second, the Best Limit Order, prices the order at the best queued price on the trader’s own side instead. A buy is priced at the current best bid, joining the queue rather than crossing it—a resting order from the moment it’s entered, not a marketable one. Neither has a precise one-word equivalent on a typical US platform. The automatic same-tick pricing is specific to this market.
Fill-or-Kill (FOK) and Immediate-or-Cancel (IOC). Standard conditional qualifiers. Legal only in the continuous session and on the last trading day of index derivatives, which is not a retail-relevant case. FOK fills the entire order immediately or cancels it entirely. IOC fills whatever it can immediately and cancels the rest.
Auction-based block trade orders exist for the derivatives market’s final trading day. They aren’t part of an ordinary cash-equity workflow—mentioned once, for completeness, and not developed further here.
A dated note on after-hours orders—the rules change on September 14, 2026. Through September 13, 2026, KRX ran a separate after-hours periodic single-price auction from 16:00 to 18:00. It cleared every 10 minutes at one price, on a ±10% band around that day’s close. Effective September 14, 2026, that auction is replaced by a continuous-matching AfterMarket running from 16:00 to 20:00, on a ±30% band around the previous day’s close—the same reference point the regular session uses. The 15:40–16:00 closing-price session is unchanged. The AfterMarket matches orders in real time, like the regular session. But its order-type menu is narrower—only the Limit Order, the Immediately Executable Limit Order, and the Best Limit Order. A plain market order and a limit-to-market-on-close order are not accepted in it, and some instrument classes, ETFs, and ETNs, among them, cannot trade in it at all.
3. Tick size: one ladder since 2023
Every price on the book has to land on a tick, the minimum increment a quote is allowed to move. Korea’s tick size isn’t flat. It widens in steps as the share price rises, on the logic that a higher-priced stock can absorb a wider absolute increment without materially changing the relative size of that increment.
Since a reform effective January 25, 2023, KOSPI, KOSDAQ, and KONEX all use the same table. Before that date the three markets ran separate, more finely stepped ladders; the exchange collapsed them into one, cutting the number of price bands and re-cutting the breakpoints. Anything describing a KOSPI-versus-KOSDAQ tick-size split, or a ladder that starts below 2,000 won, describes the pre-2023 rule and is no longer current.
| Price range (KRW) | Tick size (all three markets) |
|---|---|
| Under 2,000 | 1 won |
| 2,000 – under 5,000 | 5 won |
| 5,000 – under 20,000 | 10 won |
| 20,000 – under 50,000 | 50 won |
| 50,000 – under 200,000 | 100 won |
| 200,000 – under 500,000 | 500 won |
| 500,000 and above | 1,000 won |
At 1,346.49 KRW per USD (as of September 4, 2026), the widest tick—1,000 won, on any stock priced at 500,000 won or above—is roughly $0.74. The narrowest ordinary-equity tick, 1 won on anything under 2,000 won, is a fraction of a US cent.
ETFs and ETNs sit on their own, separate table. Since a further reform effective December 11, 2023, ETPs priced under 2,000 won trade in a 1-won tick; everything at 2,000 won and above trades in a 5-won tick, regardless of how high the price climbs. ELWs stay at a flat 5-won tick at every price, with no lower step. The narrowest tick on the market is therefore the 1-won ETP band under 2,000 won, roughly $0.0007—not the 5-won ETP/ELW tick, which is roughly $0.0037.
4. Trading unit: one share, with one exception
The trading unit, the smallest quantity an order can specify, is one share for ordinary stocks, ETFs, and ETNs. Subscription warrants, rights certificates, and beneficiary certificates all trade in units of one warrant or certificate. The one exception is the ELW (equity-linked warrant), traded in units of 10 warrants.
This is a flat, current rule with no price-based tiering. It’s worth stating plainly, because older market commentary describes a variable system: a larger minimum unit for lower-priced shares and a smaller one above a price threshold. That system no longer applies to this market’s stocks. If a source describes anything other than a flat one-share unit for ordinary equities, treat that source as describing a past rule.
Domestic fractional-share trading is not part of this system. Brokerages offering Korean retail investors fractional-share products generally do so only for overseas stocks, typically US-listed names. An order on KRX or NXT for a Korean-listed name is always denominated in whole shares.
5. NXT: a second venue, not a second copy
Nextrade (NXT) launched as Korea’s first alternative trading system on March 4, 2025. Since then, brokers can route a customer’s order to whichever of the two venues, KRX or NXT, offers the better terms at that moment through smart order routing (SOR). The pillar piece covers NXT’s existence, hours, and share of trading value. This piece covers something the pillar sets aside: the two venues do not run identical order mechanics.
NXT’s rulebook adopts KRX’s own ±30% daily price-limit band—the same cap applies on both venues, confirmed in practice when a stock printed a 29.97% pre-market move on NXT on August 6, 2026. What differs:
- NXT offers two order types KRX does not. A midpoint order, priced automatically at the middle of the current bid-ask spread—at an equal price, it fills ahead of an ordinary limit order on NXT, the reverse of the priority KRX gives a plain limit order. And a stop-limit order.
- NXT does not offer a plain market order at all on its main session—only IOC- or FOK-qualified market-type orders. A workflow built around placing a bare market order on KRX needs a substitute on NXT.
- The two venues’ Volatility Interruption resolution moves closer together on September 14, 2026—but differed before that. Through September 13, 2026, a dynamic VI trigger on NXT produces a two-minute trading halt, no auction. On KRX over that same period, the identical style of trigger converts the stock to a two-minute single-price call auction instead, detailed in How to Read Korea’s Trading Halts and Circuit Breakers. A Nextrade rulebook amendment effective September 14, 2026, replaces NXT’s flat halt with a two-minute pause resolved through a single-price call auction. That auction begins just after KRX’s own VI auction concludes, rather than running in parallel with it. The amendment also adds a static VI trigger NXT previously lacked. After that date the two venues resolve a VI in much the same way; before it, they don’t.
September 14, 2026, is not only an NXT date. The same day, KRX replaces its own after-hours periodic auction with a continuous-matching AfterMarket on a ±30% band (Section 2)—so the week’s change lands market-wide, not on NXT alone.
None of this makes one venue better than the other in general. It means an order type or a halt behavior confirmed on one venue isn’t automatically the same on the other. And a broker’s SOR routing can move an order between the two without the trader explicitly choosing.
6. Four traps investors keep falling into
Trap 1: Assuming an immediately executable limit order behaves like a fill-or-kill order. It doesn’t cancel its unfilled remainder—that remainder converts into an ordinary resting limit order at the assigned price and sits in the book like any other. A trader expecting the order to either fill completely or disappear entirely will instead find a partial position still working, quietly, at a price they didn’t type in.
Trap 2: Trying to place a market order into the close. It will be rejected. The tool for “fill me at whatever the closing price turns out to be” is the Limit-to-Market-on-Close order, submitted during continuous trading—not a market order submitted directly into the closing auction.
Trap 3: Assuming the tick-size ladder still differs by market. It did before January 25, 2023. Today KOSPI, KOSDAQ, and KONEX share one table, and a tick jump happens at 2,000, 5,000, 20,000, 50,000, 200,000, and 500,000 won—not at the older breakpoints, and not differently on the two main markets.
Trap 4: Assuming NXT is functionally identical to KRX because it quotes the same stock. The price band matches, and after September 14, 2026, the two venues’ VI resolutions mostly line up too—but the order-type menu still doesn’t. NXT has no plain market order and offers mid-point and stop-limit types, which KRX doesn’t. A workflow tested only against KRX can behave unexpectedly the first time an order is routed to NXT.
7. FAQ
What decides which order gets filled first in Korea’s continuous session?
Price priority first: the better-priced order wins, then time priority among orders at the same price. This is the standard logic used across most developed markets. A low-liquidity or newly designated issue is the exception—it trades in a periodic single-price auction instead of continuous matching, on a call roughly every 10 to 30 minutes.
What’s the difference between the Immediately Executable Limit Order and the Best Limit Order?
The Immediately Executable Limit Order prices a buy at the best available ask and a sell at the best bid and fills against the opposite side immediately—with any unfilled remainder converting into an ordinary resting limit order at that price, not cancelled. The Best Limit Order prices the order at the best queued price on the trader’s own side instead, joining the resting queue rather than crossing it from the moment it’s entered. Both exist only in the continuous session.
Can I place a plain market order on NXT?
No. NXT’s main session accepts only IOC- or FOK-qualified market-type orders, not an unqualified market order. On KRX, a plain market order is legal only in the opening auction and the continuous session. It is not accepted in the closing auction, in block or basket trades, or in after-hours trading—and that covers both the periodic call auction through September 13, 2026, and the continuous AfterMarket that replaces it from September 14, 2026.
Why does the tick size matter if I’m not a high-frequency trader?
It sets the smallest price improvement available on any order and the smallest gap that can exist between the best bid and ask. Since the January 2023 reform, a stock priced at 500,000 won or above moves only in 1,000-won increments on any of Korea’s three equity markets—a wide grid compared with the 1-won tick available on an ETF priced under 2,000 won.
How does this connect to the rest of the site?
This is the deep dive on one part of the pillar, How Korea’s Trading Day Works, which walks a single order through venues, sessions, halts, and settlement. How to Read Korea’s Trading Halts and Circuit Breakers covers what happens when a price move is large enough to trigger a halt, rather than simply moving through the book at the tick sizes described here.
Last updated: September 7, 2026
This article is for informational purposes only and does not constitute investment, tax, or legal advice. It describes general order-type and market-structure mechanics on the Korea Exchange and Nextrade and is not a recommendation about any security, order type, or trading strategy. Order-type availability, tick sizes, and venue-specific mechanics can change; verify current KRX and NXT rules and your broker’s own order-routing behavior before relying on them.