Who Investigates Insider Trading? The Real Map

Who investigates insider trading in the United States?

The main insider-trading investigators are the SEC, DOJ, FINRA, securities exchanges, and sometimes foreign regulators. The SEC's Division of Enforcement is the civil enforcer. DOJ's Market, Government, and Consumer Fraud Unit and U.S. Attorney offices handle criminal prosecution. FINRA's insider-trading detection program watches trading patterns and refers cases.

The split matters because "investigates" can mean different things. A suspicious options trade before an acquisition may first appear in market surveillance. A whistleblower may send a tip to the SEC. A criminal case may later run beside a civil SEC complaint. A public Form 4 may explain a lawful insider transaction, while the absence of a Form 4 does not prove wrongdoing.

What does each investigator actually do?

Each investigator owns a different part of the chain. The SEC can subpoena records, take testimony, file civil complaints, seek injunctions, disgorgement, penalties, officer-and-director bars, and administrative orders. DOJ can bring criminal securities-fraud, wire-fraud, obstruction, money-laundering, and conspiracy charges when prosecutors believe the evidence supports proof beyond a reasonable doubt.

FINRA is different. It is not the criminal prosecutor and it is not the SEC, but its market-surveillance role is central. FINRA says its insider-trading program monitors 100% of trading in stocks, options and bonds around material news events and produces hundreds of referrals to the SEC and law enforcement each year. That makes FINRA one of the main discovery engines.

How does a case usually start?

An insider-trading case usually starts with a trading pattern, a tip, a broker-dealer escalation, a company event, or a regulatory data match. The SEC's Submit a Tip or Complaint page explicitly includes possible insider trading among the securities-law violations the public can report. The SEC's Whistleblower Program adds incentives and protections for original, timely, credible information.

Market data can start the other path. FINRA described its program as connecting trading data, public information, company information, and FINRA-firm information into actionable intelligence. In a 2026 civil case, the SEC said its complaint against 21 individuals came from the Enforcement Division's Market Abuse Unit and noted parallel criminal charges by the U.S. Attorney's Office. It also thanked FINRA, the FBI, and foreign regulators in the same SEC insider-trading case announcement.

What data do investigators use?

Investigators use trade and order data, account records, communications, issuer records, event timelines, public filings, broker supervisory records, and sometimes cross-border assistance. Public data is not enough to prove intent, but it is enough to create a disciplined question.

Arkolith's production database estimated about 9.1 million insider-transaction rows, 3.8 million filing-event rows, and 4.1 million source-record rows on August 18, 2026. The latest insider transaction date in that read was August 17, 2026. That public-record layer is not an accusation machine. It is a way to separate disclosed transactions, suspicious timing, and missing evidence before anyone writes a claim.

The first public record to understand is Form 4. The SEC's officers, directors and 10% shareholders guidance says Section 16 insiders generally report most company-equity transactions within two business days on Forms 3, 4 or 5. Read that beside how insider trading is detected, the Form 4 data layer, Form 4 transaction codes, and 10b5-1 plans before treating any trade as suspicious.

What is the difference between civil and criminal insider trading?

Civil and criminal insider-trading cases can involve the same facts, but they use different authorities, burdens, and remedies. The SEC brings civil enforcement actions under the federal securities laws. DOJ brings criminal cases when prosecutors pursue punishment through the criminal courts.

That distinction explains why some announcements mention both. The SEC may sue for civil penalties and disgorgement while a U.S. Attorney charges the same defendants criminally. A civil complaint is not a conviction. A criminal indictment is still an allegation until a plea or verdict. Good analysis keeps those labels visible rather than turning every enforcement document into a guilty finding.

The SEC's fiscal 2025 enforcement results said abusive trading, including insider trading and market manipulation, remained central to enforcement. The same SEC FY2025 enforcement results also described specific insider-trading charges during that year. That is a docket signal, not a forecast about any single company.

How should an analyst check a suspicious trade?

Start with the public clock. Identify the issuer, event date, transaction date, filing date, accepted time, trade code, role of the reporting person, and whether the transaction was under a 10b5-1 plan. Then ask whether the trade was open-market, grant-related, option-related, gift-related, or mechanical. The public insider activity pages and Section 16 officer guide help keep that sorting honest.

For agent workflows, the useful output is not "this looks illegal." It is a source packet: ticker, insider, role, transaction code, transaction date, filing accepted time, source URL, nearby material event, and explicit uncertainty. Use the insider trading data API for API selection, or start at /connect and the quickstart when an agent needs source-linked tool calls. The public MCP API catalog identifies the machine-readable insider and provenance surfaces.

One citable rule: a Form 4 can prove that a covered insider reported a transaction on a public filing clock, but it cannot prove the insider traded on material nonpublic information.

Frequently asked questions about insider-trading investigations

Does the SEC or FBI investigate insider trading?

The SEC investigates and brings civil insider-trading enforcement cases. Criminal investigations may involve DOJ, U.S. Attorney offices, the FBI, and other law-enforcement partners, often in parallel with SEC civil actions.

Does FINRA investigate insider trading?

Yes. FINRA surveils U.S. markets for suspicious trading around material events and sends referrals to the SEC and law enforcement. It is a discovery and referral engine, not the final criminal prosecutor.

Can a Form 4 prove insider trading?

No. A Form 4 proves a reported insider transaction and its filing clock. It does not prove the trader had material nonpublic information, acted with scienter, or broke the law.

What should I report if I suspect insider trading?

Use official channels, not social posts. The SEC tip and whistleblower systems ask for specific, timely, credible information. Dates, account records, communications, source documents, and event chronology matter more than a vague claim.

This article explains public enforcement and data workflows. It is not investment advice, legal advice, tax advice, or a recommendation to buy or sell any security.