South Korea’s financial authorities have referred four cases of unfair virtual asset trading to investigative agencies, including one involving two brothers who used automated API trading to inflate prices before selling their holdings.
The Financial Services Commission and the Financial Supervisory Service announced the referrals on Tuesday, September 23. The cases include three instances of short-term price manipulation and one case of misconduct and price manipulation by executives of a virtual asset management company. None of the parties has been named, which is standard practice while investigations are pending.
How the brothers’ scheme worked
In the most detailed case, two brothers used identical methods to accumulate assets rapidly and then employed API-enabled automated trading programs to create the appearance of active trading. The artificial activity drove prices to their target levels, at which point the pair sold their entire holdings into the demand they had manufactured. Retail traders who bought during the run-up were left holding assets whose apparent momentum was an illusion.
The other manipulation cases followed similar patterns. One involved using multiple accounts to circumvent API order limits that exchanges apply to single traders. Another involved inflating trading volumes to meet exchange listing requirements, a practice that makes a token look more liquid than it is and can help it pass listing reviews that depend on volume thresholds. A third case again involved short-term price manipulation designed to lure retail investors into buying through the trading screen, according to the Chosun Biz report.
South Korea’s Virtual Asset User Protection Act, in force since July 2024, defines six categories of unfair trading for the first time in Korean law, including market manipulation, trading based on undisclosed material information, and fraud. Violations carry criminal penalties of up to life imprisonment for the most serious cases, alongside unlimited fines tied to illicit gains. Before the law passed, prosecutors had to stretch general fraud and capital markets statutes to reach crypto conduct, which made cases slow and outcomes uncertain.
Why API trading sits at the center
The cases highlight a recurring problem in crypto surveillance. API access exists for legitimate reasons, from institutional execution to portfolio management tools, but the same channel allows a trader to submit far more orders than a human could, layering fake buy and sell sides to paint a picture of demand that does not exist.
Exchanges impose order limits and rate caps to slow this down, but the referred cases show the controls are circumventable with multiple accounts. Detection therefore depends on linking accounts that behave in a coordinated way, which is harder across platforms and easier when the activity stays on one exchange, as it did here. The FSC has pushed licensed operators to strengthen account-linking analytics, and Tuesday’s referrals suggest the monitoring pipeline is catching coordinated behavior.
Korean authorities have built the referral pipeline precisely for this. The FSC and FSS review trading data submitted by licensed operators, identify patterns that fit the statutory definitions of unfair trading, and hand the cases to prosecutors and police. Tuesday’s batch is the latest in a steady stream since the law took effect, and the pace of referrals has increased as operators file more complete surveillance data.
Context: a market under watch
The referrals land during a period of heavy regulatory activity in Seoul. The country’s won-token race has accelerated, with Kakao Pay and KakaoBank signing a stablecoin memorandum with Fireblocks this week to test stablecoin infrastructure. The Bank of Korea is piloting 24-hour won settlement for foreign investors. Institutional participation is growing, and with it the stakes of keeping retail markets clean.
The timing also follows a stretch of enforcement headlines elsewhere. Hong Kong’s SFC listed Vebit as a suspicious virtual asset trading platform this week, and Hong Kong is preparing to submit its virtual asset service provider framework by the end of 2026. The US CFTC issued staff guidance that certain prediction market contracts are presumptively susceptible to manipulation. Poland charged a former police officer in the sprawling Zondacrypto collapse investigation. Manipulation cases are moving from theoretical concern to prosecuted reality in multiple jurisdictions at once.
For Korean exchanges, the message is that API surveillance obligations are being tested against real schemes, and that the referral mechanism is producing charges rather than warnings. For traders, the message is blunter. The kind of wash trading that passed for marketing in earlier cycles now ends in a prosecutor’s office, and the two-year-old legal framework gives investigators tools that did not exist before 2024.
What happens next
The referred cases go to investigative agencies, which can summon the parties, seek search warrants and eventually bring indictments. Sentencing under the Virtual Asset User Protection Act depends on gains and severity, with the heaviest penalties reserved for organized manipulation. The FSC said it will continue monitoring unfair trading practices and referring cases as they are identified.
The executives case will be watched most closely, since misconduct by a management company’s own officers cuts against the industry’s argument that self-regulation works. If prosecutors charge named executives under the new law, it would be among the first such cases and would set the tone for how seriously Seoul intends to police its licensed virtual asset managers.
Market reaction has been muted, as expected for enforcement news that names no listed entities. Korean crypto-linked equities traded in line with the broader market on Tuesday, and the won held steady. The cases matter for the precedent they set, not for the tickers they touch today.