DART insider filings explained: how Korean ownership disclosure works

What DART is and who runs it

DART stands for Data Analysis, Retrieval and Transfer System. It is the electronic disclosure system operated by the Financial Supervisory Service (FSS), Korea's integrated financial regulator, and it is the one place every mandatory corporate filing lands. Companies submit online and the document becomes available to investors immediately. If a Korean listed company reported something to a regulator, it is on DART.

The public portal is dart.fss.or.kr. Foreign readers can use the English mirror at englishdart.fss.or.kr, which exposes report titles, attachments and a built-in translation function, though the deepest coverage remains in Korean. DART is where the raw facts live: periodic business reports, material-event disclosures, and the ownership and insider reports this guide is about.

The rules themselves do not come from DART. They come from the Financial Investment Services and Capital Markets Act (FSCMA), the statute most English sources shorten to the Capital Markets Act. The FSS runs the pipes; the FSCMA and its Enforcement Decree set who must report what, and by when. The Financial Services Commission (FSC) is the policymaking body above the FSS, and the Securities and Futures Commission investigates violations.

Who must file: the report on ownership of specific securities

The core insider-ownership duty sits in FSCMA Article 173. When a person first becomes a corporate insider of a listed company, they must report their ownership of that company's "specific securities" to the Securities and Futures Commission, through the FSS, and to the Korea Exchange. Every subsequent change in that ownership must also be reported.

Two categories of person are caught:

• Executives (officers): directors, auditors, and employees exercising supervisory authority. In practice this is the registered management of the issuer.
• Major shareholders: holders of 10 percent or more of the voting shares, plus anyone who exercises de facto influence over major management matters such as the appointment or dismissal of officers, even below 10 percent.

"Specific securities" means the equity securities of the company itself and instruments tied to them, held by these insiders. The report is the Korean analogue of a US Form 4 combined with the initial Form 3: it establishes the insider's starting position and then tracks every move.

The five business day deadline

Both the initial report and each change report are due within five business days. That is slower than the US Form 4 two-business-day clock but broadly in line with Europe's MAR three-trading-day rule and Canada's SEDI five-day window. The count runs in business days, so weekends and Korean public holidays extend the real-world wait.

The 5 percent rule: the large-holding report

Running in parallel, and often confused with the insider report, is the "5 percent rule," the large-holding or mass-holding disclosure under FSCMA Article 147. It is an ownership-concentration rule, not an insider-status rule, so it can catch outside investors who hold no office at all.

Anyone whose holding of a listed company's voting equity, aggregated with related parties and persons acting in concert, reaches 5 percent or more of the total outstanding must report to the FSC and the Korea Exchange. The report states the size of the stake and its purpose, in particular whether the intent is to influence control of the issuer. After that first report, any change of 1 percent or more in the holding, or any change in the stated purpose, triggers a fresh report.

The plus or minus one percent trigger

The standard deadline for both the initial 5 percent report and each 1 percent change report is five business days from the trade date. There is an important relaxation: passive investors who hold with no intent to control management, and certain professional investors specified in the FSCMA, get an extended clock. For them the report can run to as late as the tenth day of the month following the quarter in which the change occurred. This is why an activist stake shows up on DART within days while a passive index fund's crossing may surface weeks later. Missing the deadline is serious: sanctions can include fines, criminal liability, and suspension of voting rights on the unreported shares above 5 percent.

The 2024 prior-disclosure regime for large insider sales

Korea added a forward-looking layer on 24 July 2024. Under an FSCMA amendment, executives and major shareholders (again, 10 percent or de facto controllers) of listed companies must now disclose certain planned trades in advance, rather than only after the fact. The disclosure states the purpose, price, quantity and trading period, and it must be filed at least 30 days before the trade begins.

The advance duty does not apply to every trade. It is triggered only when the aggregate volume and value of the insider's transactions over the preceding six months exceed both of two thresholds: 1 percent of total issued shares, and KRW 5 billion. The six-month aggregation is deliberate, designed to stop insiders from slicing a large sale into small pieces to duck the rule. The policy motive was blunt: repeated sharp price drops caused by large, unannounced insider sales. For a reader watching DART, this means the biggest insider disposals are now visible as intentions weeks before they hit the market.

The short-swing profit return rule

The FSCMA also carries a short-swing profit return rule, Korea's counterpart to US Section 16(b). If an insider realizes a profit from buying and selling (or selling and buying) the company's equity securities within a six-month window, the company can require that profit to be returned, regardless of whether any inside information was actually used. Procedures sit in the Regulations on Return of Short-Swing Profit, Investigations and Report on Unfair Trades. It is a strict, mechanical clawback layered on top of the disclosure duties, not a substitute for them.

How to read a DART insider filing

Insider and ownership reports on DART share a common spine. The fields that matter most to an outside reader:

Read the report type first: a 5 percent large-holding report and an Article 173 insider report look similar but answer different questions, one about concentration and control intent, the other about insider status. The stated purpose field on a 5 percent report is where an activist campaign announces itself.

Interpretation traps

Two regimes, one dataset

The 5 percent rule and the insider-ownership report are separate obligations with separate triggers. A 12 percent founder can generate both an Article 147 large-holding report and an Article 173 insider report for the same trade. Counting them as two independent signals double-counts one economic event.

The passive-investor delay

Because passive and professional holders can report on the extended quarterly cycle, absence of a recent 5 percent filing does not mean no one crossed the line. A stake built quietly by an index manager can sit undisclosed until the following quarter. Do not read filing silence as trading silence.

Advance disclosures are intentions, not fills

A prior disclosure under the 2024 regime is a plan filed at least 30 days ahead. The trade may execute at a different size, at a different price, or across a spread-out window, and plans can be revised. Treat the advance notice as a signal of intent, not as a completed transaction.

Purpose can change without a trade

Under the 5 percent rule, a shift from a passive "simple investment" purpose to an active "influence over management" purpose is itself reportable, even with no change in share count. A new filing can therefore mark a strategy pivot rather than any buying or selling.

Non-market rows carry no price signal

Inheritances, gifts and in-kind transfers are all reportable and move the ownership percentage, but they are not market trades. They say nothing about what the insider would pay for the stock, and they should not be read alongside open-market buys as if they were the same act.

How insiders-trades.com tracks DART

We ingest Korean insider and ownership reports straight from DART, the FSS disclosure portal, and normalize the roles (officer, auditor, major shareholder, concert party) into the same taxonomy we apply across 28 regulators, so a Korean director and a US officer land in the same bucket. Because Korea splits its rules across the Article 173 insider report, the Article 147 large-holding report and the 2024 prior-disclosure regime, we key on the underlying filer and issuer rather than the form name, which keeps a single insider's activity together across all three tracks.

Browse the live output on the Korea market hub, or start from a company page such as NAVER, Samsung Electronics or SK Hynix. For a sense of what a large institutional filer looks like under the 5 percent rule, see the National Pension Service, one of the most frequent large-holding reporters on the Korea Exchange.

To compare the mechanics with other markets, read our SEC Form 4 guide for the United States and our EDINET guide for Japan's neighboring large-shareholding regime, or step back to the insider disclosure rules by country index.