# The Bithumb Squeeze: How Korea's #2 Exchange Surged, Stalled, and Reset the Listing Game

*ium Research — James, Co-Founder — June 18, 2026*
*Canonical: https://iumlabs.io/blog/bithumb-upbit-squeeze-korea-exchange-duopoly-2026*

## Key Takeaways

- Korea's exchange market is a duopoly, Upbit and Bithumb together hold north of 87% of won volume, but the split between them is the most volatile number in Korean crypto
- Bithumb clawed from roughly 26% to a 45.6% single-day peak in September 2025 on zero-fee campaigns and aggressive listings, then a March 2026 AML suspension reversed the momentum
- The two venues now play different games: Upbit is the deep, defensive price-discovery pool; Bithumb is the faster, promotional challenger carrying a regulatory overhang
- For a project choosing where to list, the decision is no longer "the big one," it is a liquidity-versus-speed trade with a banking-risk asterisk on Bithumb

For years the Korean exchange question had one answer: list on Upbit, and if you can, Bithumb too. The hierarchy felt permanent. Then 2025 happened. Bithumb went on the offensive, the gap with Upbit nearly closed on some days, and the duopoly briefly looked like a race. Then a regulator stepped in. The story of how Bithumb surged and stalled is the story of how listing strategy in Korea actually works.

## 1. A Duopoly, Not a Monopoly

Start with the structure. Upbit has dominated for years, peaking above 80% of domestic volume in early 2024, but its share compressed as Bithumb fought back. By 2026 the two together control more than 87% of all won-denominated volume, and after foreign venues like Binance, OKX, and Bybit were pulled from Korean app stores in January 2026 for failing to register, that duopoly is effectively sealed. Everyone below the top two, Coinone, Korbit, and GOPAX, splits low single digits.

> **87%+** — Share of Korean won crypto volume Upbit and Bithumb together control in 2026, a duopoly foreign exchanges can no longer touch after the January 2026 app-store delistings (Source: Tiger Research)

## 2. The Surge and the Reversal

The headline of 2025 was Bithumb refusing to stay second. Official first-half data put Upbit at 71.6% and Bithumb at 25.8% of volume. Then Bithumb waived trading fees on 200 coins in its won market in September 2025, and the gap collapsed.

| Item | Value |
|---|---|
| H1 2025 | 25.8 |
| Sept 9 2025 peak | 45.6 |
| Q4 2025 | 31.1 |

*Bithumb's share of Korean spot volume swung hard across 2025, %. (Source: FSS, Mobile Index, CoinGecko)*

The peak did not hold. By the fourth quarter Bithumb settled near 31% against Upbit's 65%, and the depth gap stayed wide.

| Item | Value |
|---|---|
| Upbit | 3.36 |
| Bithumb | 1.2 |

*Average daily trading volume, first half 2025, $B. (Source: FSS via Cryptonews)*

> **45.6%** — Bithumb's single-day share of Korean spot volume on September 9, 2025, within six points of Upbit before the gap reopened (Source: Mobile Index via BeInCrypto)

Then came the reset. In March 2026 the Financial Intelligence Unit fined Bithumb 36.8 billion won (about $24.6M) and imposed a six-month partial suspension on onboarding new transfer users, over roughly 6.65 million AML violations. A separate February 2026 system error briefly credited users some 620,000 BTC during a promotion. Momentum swung back to Upbit.

> **36.8B won** — Fine (~$24.5M) plus a six-month partial business suspension (Mar 27-Sep 26, 2026) the FIU handed Bithumb over roughly 6.65 million Specific Financial Information Act violations, the event that reversed its momentum (Source: [FSC sanction notice](https://www.fsc.go.kr/no010101/86467))

> **"Suspension of business days for 6 months, and a total fine of 36.8 billion won."**
>, FSC/KoFIU sanction notice on Bithumb, March 17, 2026 (translated from the Korean original)

## 3. How the Two Venues Differ

| Dimension | Upbit | Bithumb |
|---|---|---|
| Q4 2025 market share | 65.0% ($180.7B) | 31.1% ($86.5B) |
| Share of users (H1 2025) | 53% of 10.17M | 37% of 10.17M |
| Banking partner | K Bank | KB Kookmin (from NH NongHyup, Mar 2025) |
| Listing posture | Reactive, broad defensive listings | Aggressive, lists first, zero-fee campaigns |
| Public-market path | Listing via Naver Financial tie-up | IPO slipped to after 2028 |
| 2026 development | Gaining share post-suspension | $24.6M AML fine, 6-month partial suspension |

The clearest behavioral split is listing posture. Bithumb is the aggressor, listing more new tokens than Upbit through 2025 and chasing competitively traded coins; Upbit defends, often listing the same names shortly after to neutralize the edge. Both moves matter to a project, because a fresh listing on either venue routinely triggers a double-digit price reaction, with one recent token jumping 43% on its listing day.

## 4. What It Means for Projects

The "where to list" question now has structure. Upbit is the deeper pool and the price-discovery venue: you go there for liquidity, credibility, and the cleanest reference price. Bithumb is faster to engage, more willing to run promotional muscle behind a listing, and hungry for share, which can mean more marketing lift for a new pair. The asterisk is regulatory: Bithumb's six-month onboarding suspension and a June 2026 bank audit that shortened its real-name account renewal to six months put a question mark on KRW-access continuity that Upbit does not carry right now. The realistic playbook for a serious token is still both venues, sequenced, with Upbit as the anchor and Bithumb as the amplifier. Our read on the broader [Upbit dominance dynamic](/blog/upbit-dominance-how-78-percent-market-share-reshapes-token-economics) and the mechanics of a [Korean listing](/blog/korean-exchange-listing-strategy-upbit-bithumb-2026) go deeper on sequencing.

## 5. What Breaks It

Three things undercut the "Bithumb is catching up" narrative. First, the surge was bought: zero-fee campaigns and listing aggression lift share while they run and fade when they stop, and the AML suspension stopped the engine. Second, the share numbers are measurement artifacts as much as facts, since a 45.6% day on Mobile Index sits next to a 31% quarter on CoinGecko, so anyone quoting one number is choosing a window. Third, the structural constraints bind both venues equally: a single-bank rule, a new 20% ownership cap with a three-year clock, and banking partners that can shorten or pull real-name account contracts. Bithumb's IPO, once slated for 2025, has slipped to after 2028, which tells you how much of the comeback story is still aspiration.

*[Figure: FSS DART, Dunamu Q1 2026 quarterly report (filed May 15, 2026). We read the filings so you don't have to.]*

## 6. How We Run It

We treat exchange selection as a sequencing problem, not a popularity contest. That means [exchange marketing](/services/exchange-marketing) tuned to each venue's audience, [listing support](/services/listing) that reads the current regulatory state of each exchange rather than last year's hierarchy, and timing that puts the amplifier listing where it does the most work. If you are mapping a Korean listing across Upbit and Bithumb, that is the [conversation to start](/contact).

## Sources

Market share and volume: [Cryptonews via Yahoo Finance, "Upbit corners 72% of Korean crypto"](https://finance.yahoo.com/news/upbit-corners-72-korean-crypto-233000204.html), [KuCoin via Odaily on Q4 2025 share](https://www.kucoin.com/news/flash/upbit-s-dominance-in-south-korean-crypto-market-declines-in-q4-2025), and [Tiger Research via CoinGecko, 2026 Korea market guide](https://www.coingecko.com/learn/2026-korea-crypto-market-guide-tiger-research). Zero-fee campaign and the September 2025 spike: [BeInCrypto](https://beincrypto.com/bithumb-launches-fee-free-campaign-to-upturn-upbit/). AML fine and IPO delay: [The Block](https://www.theblock.co/post/396088/bithumb-crypto-exchange-stretches-ipo-timeline-2028). Banking partners and the single-bank rule: [Korea Times](https://www.koreatimes.co.kr/business/banking-finance/20260328/banks-push-ahead-with-crypto-exchange-partnerships-despite-reputational-risks). Figures are point-in-time and swing with the measurement window.

*This report reflects ium Labs' operating view and is intended for general information, not investment advice.*