Three rules explain most of what looks strange about a Korean IPO to a foreign investor: at least half of the retail tranche is allocated by equal allotment regardless of how much money you commit — with a random draw deciding only when eligible subscribers outnumber those shares — the debut session lets the stock trade anywhere between 60% and 400% of its offer price in place of ordinary daily price limits (though volatility-interruption mechanisms can still briefly pause matching), and locked-up shares are released on a published, staggered lockup calendar that any investor can look up before listing day. Master those three mechanisms and the seemingly chaotic first weeks of a Korean new listing become much easier to read as supply-and-demand arithmetic — though never fully predictable.
The Korean IPO pipeline at a glance
A Korean IPO on the KOSPI or KOSDAQ market runs through a fixed sequence, each step producing a public disclosure you can read on the Korea Exchange (KRX) data portal or in the issuer’s registration statement:
- Securities registration filing. The issuer and its lead underwriter file a prospectus containing the indicative price range and the share allocation between tranches. The full lockup schedule cannot appear at this stage, because institutional holding pledges are submitted during book-building; the completed schedule shows up in the amended and final disclosures filed after book-building, still before listing day.
- Institutional book-building (sugyo yecheuk, demand forecasting). Institutions submit price and quantity bids over roughly a week; the final offer price is set from this book.
- Retail subscription (cheong-yak, the public subscription). Usually a two-day window a few days after pricing.
- Listing and first-day session. Typically about a week after subscription. Throughout the debut session, the stock can trade anywhere within 60–400% of the offer price.
- Lockup expirations. Pledged shares unlock in tranches — commonly around 15 days, 1 month, 3 months, and 6 months after listing.
Everything below is a closer look at steps 2 through 5, because that is where the tradable edges and the common mistakes live.
Book-building and the mandatory holding pledge
Korean book-building has a feature with no close US equivalent: the uimu boyu hwagyak, or mandatory holding pledge. When institutions bid in the book, they may voluntarily pledge to hold their allocated shares for a stated period — typically 15 days, 1 month, 3 months, or 6 months. Underwriters reward longer pledges with larger allocations, so the pledge ratio becomes a visible quality signal.
How to read it: there are two related but distinct numbers, and it pays not to conflate them. During book-building, the pledge ratio measures the share of institutional bids — requested quantities, not final holdings — that carried a holding commitment. After allocation, the post-book-building disclosures report the shares actually allocated subject to lockup, which is the figure that determines real supply. Historically, deals seen as strong have drawn holding pledges on a large share of institutional demand, and correspondingly more of the allocated stock ends up under lockup. A high pledged-allocation share means less stock can legally hit the market in week one — supportive for the debut, but it also means the unlock dates later carry proportionally more supply. A low pledged share means institutions can sell from the first session onward. Neither is ‘good’ in the abstract; each just shifts when the supply arrives.
The retail cheong-yak: half equal allotment, half proportional
The retail tranche — typically around a quarter of the offered shares — is split into two allocation methods since a structural reform in the early 2020s:
- Equal allotment (gyundeung baejeong): at least 50% of the retail tranche is divided equally among every valid subscriber who committed at least the minimum. Only in hot deals where subscribers outnumber these shares does allocation become a literal lottery — many applicants receive one share or zero, decided by random draw.
- Proportional allotment (biryae baejeong): the remainder is allocated in proportion to the subscription deposit you post. Retail subscribers must post a deposit (cheong-yak jeunggeogeum) of 50% of the value of the shares they apply for; unallocated deposits are refunded within days.
The practical consequences:
- Small accounts get meaningful access. Committing the minimum lot puts you in the same equal-allotment pool as someone committing far more.
- Large accounts face brutal dilution on the proportional side in popular deals. Competition ratios in the hundreds-to-one are routine for well-received listings, meaning enormous deposits yield only a handful of shares.
- Subscription windows pull outside cash into brokerage accounts. Investors transfer money in from bank accounts to fund the 50% subscription deposit, lifting the aggregate investor-deposit figure — a statistic published by the Korea Financial Investment Association (KOFIA) — around large IPO windows; once refunds are paid and cash flows back out to bank accounts, the aggregate recedes. More on reading that number below.
The 60–400% debut range, introduced in June 2023
Before mid-2023, Korean listings opened within 90–200% of the offer price and were then subject to the ordinary daily price limit, producing the famous ttasang pattern — slang for opening at double the offer price and then rising to the first-day 30% limit-up, leaving no tradable liquidity for the rest of the session. In June 2023 the Korea Exchange widened the first-day range so that a new listing can trade anywhere between 60% and 400% of the offer price throughout the debut session, replacing ordinary daily price limits for that session. (Standard volatility-interruption mechanisms can still pause matching briefly within the session.)
What this changes in practice:
- Price discovery compresses into day one. Instead of a debut capped by the old double-open-plus-limit-up ceiling with almost no tradable volume, the market can now clear at (up to) four times the offer price within the first session. First-day volatility is higher, but the untradeable first-day squeeze is largely gone.
- The 400% print is a ceiling, not a target. A common newcomer mistake is treating the top of the range as the expected outcome for any oversubscribed deal. Most listings clear well inside the range; the ceiling only binds on the most crowded debuts.
- The 60% floor matters too. Weak deals can — and do — trade below offer price on day one. The range permits the market to trade below the offer price as well as above it — room to disagree with the underwriter in either direction.
- Flipping economics changed. Under the old regime, allocation winners often sat through a limit-locked debut with little liquidity to sell into. Now the rational sell decision concentrates on the first session, which is one reason first-day volume in Korean IPOs is typically enormous relative to float.
Lockup releases: the published supply calendar
Because holding pledges are tiered, every Korean IPO comes with a supply schedule you can read in advance. A typical structure looks like this (illustrative tiers, not a specific deal):
| Time after listing | Who unlocks | What to check in the disclosures |
|---|---|---|
| Listing day | Unpledged institutional allocations, retail shares | Effective free float on day one (often well under half of shares outstanding) |
| ~15 days / 1 month | Short-pledge institutions | Share count unlocking as % of float, not of total shares |
| ~3 months | Mid-tier pledges | Whether the stock still trades far above offer price (unlockers sit on gains) |
| ~6 months | Long-pledge institutions, often pre-IPO financial investors | Frequently the largest single tranche |
| ~1 year+ | Controlling shareholders (customary voluntary lockup); employee stock ownership shares, which generally carry a holding restriction of around one year | Rarely sold immediately, but removes the legal barrier |
How to use it: compute each unlock as a percentage of the tradable float at that date, not of total shares outstanding. An unlock equal to 5% of shares outstanding can be 20% of the actual float in a tightly held name. The overhang effect is strongest when (a) the unlock is large relative to float, (b) the stock trades far above the offer price so unlockers are sitting on profits, and (c) pre-IPO financial investors — whose mandate is to exit — dominate the tranche. When all three align, weakness into and around the unlock date is a pattern many Korean small-cap traders watch closely — though it is far from guaranteed, and outcomes vary widely from deal to deal. It is also widely anticipated, so any move often front-runs the date itself.
Worked example: reading investor deposits as an IPO demand gauge
KOFIA publishes aggregate customer deposits at brokerages (tuja-ja yetak-geum, investor deposits) — the idle cash sitting in trading accounts. As of 2026-09-16, that figure stood at roughly 99.57 trillion won. Here is how to read it in an IPO context, step by step:
- Treat it as the ammunition pool. Retail cheong-yak deposits are funded out of this cash, plus whatever investors transfer in for the occasion. The figure tells you how much idle brokerage cash is sitting in accounts at a given moment; whether that level is high or low is only meaningful against a historical series, which is worth pulling from KOFIA before drawing conclusions.
- Watch the transfer-and-refund pattern. Around a blockbuster subscription window, the aggregate rises as investors move cash in from bank accounts to fund the 50% deposit requirement; after allocation, refunds land back in brokerage accounts, and much of that cash then flows back out to banks, so the aggregate falls back within days. A rise that does not fully reverse suggests some of that cash stayed in the market.
- Pair it with margin balances. Outstanding margin loans stood at about 33.07 trillion won as of the same date (2026-09-16). Rising deposits alongside rising margin debt signals aggressive risk appetite — the environment in which debut prices push toward the upper half of the 60–400% range. High deposits with flat or falling margin debt suggests cash is parked, not committed.
- Scale it against the deal. A subscription that attracts deposits equal to a meaningful fraction of the national pool is, by definition, a crowded deal — expect random-draw-level equal allotment and severe proportional dilution.
For context on the broader tape: the KOSDAQ index — home to most Korean IPO volume — closed at 815.98 on 2026-09-16, and the won was trading around 1,377 per dollar as of the 2026-09-17 session. Neither number changes the mechanics above, but currency levels matter if you are a foreign subscriber funding a won deposit.
Common mistakes to avoid
- Reading competition ratios as return forecasts. A huge subscription ratio predicts allocation scarcity, not aftermarket performance. Crowded deals can and do break below offer price once flippers sell.
- Ignoring the pledge ratio. Two deals with identical subscription demand behave very differently on day one if one has most institutional stock pledged and the other has none.
- Measuring unlocks against total shares. Always use float. This single correction changes many ‘small’ unlocks into large ones.
- Assuming the old ttasang playbook still applies. Post-June-2023, the old first-day double-open-plus-limit-up constraint is gone; price discovery now happens within the 60–400% range, and the debut session itself is the event.
FAQ
Can foreign investors participate in the retail cheong-yak?
The retail subscription is run through Korean brokerage accounts, so participation requires a local account. Korea abolished its long-standing foreign investor registration requirement in December 2023; non-residents can now open accounts using standard identification — a passport number for individuals or a legal entity identifier for institutions — through brokers that onboard foreign clients. Most global institutions instead access Korean IPOs through the institutional book-building tranche; many foreign individuals simply trade the name after listing.
Why do Korean IPOs often open on enormous volume?
Day-one float is small (lockups withhold much of the register), equal-allotment winners hold tiny positions they are inclined to flip, and the 60–400% first-session range concentrates price discovery into one session. Large volume against a small float is the structural result, not necessarily a signal.
Where do I find a specific deal’s lockup schedule?
In the amended and final registration disclosures filed after book-building — the stage at which institutional holding pledges are actually submitted — summarized in the listing documents on the KRX data portal. The completed schedule lists each pledge tier, share count, and release date, and it is public before the stock ever trades.
Is the 60–400% range still in force?
Yes — the special first-session price range of 60–400% of the offer price has governed debut sessions on KOSPI and KOSDAQ since its introduction in June 2023 and remains the rule as of September 2026. After the first session, normal daily price limits apply.
Sources
- KRX data portal — listing statistics and disclosures: data.krx.co.kr
- KOFIA statistics — investor deposits and margin balances: freesis.kofia.or.kr
- Naver Finance — per-deal subscription and price data: finance.naver.com
- Bank of Korea ECOS — macro and FX reference series: ecos.bok.or.kr
Disclaimer: This is an information and analysis publication, not investment advice. See our Methodology for data sources, standards, and our corrections policy.