Where the accusation comes from
Market manipulation allegations can originate in several places at once. A firm's own surveillance may flag orders placed and canceled before execution, trading around a closing price, or activity across related accounts, and the compliance department then asks questions. Counterparties, issuers, or investors may make the accusation in a demand letter or a civil complaint. FINRA, the exchanges, the SEC, and the CFTC for futures and commodities may be watching the same data. The SEC and CFTC bring civil enforcement; criminal cases usually come from the Department of Justice, though New York prosecutors can also bring them. Whatever the source, the central issue is usually intent, meaning whether the trading aimed to send false signals to the market or had a legitimate purpose.
Your job and your registration
For registered individuals, an internal allegation can carry consequences before any regulator acts. A firm that terminates or permits the resignation of a registered person files a termination notice with FINRA that can disclose an internal review, and that language follows you to later employers. Inaccurate disclosures can sometimes be challenged through FINRA arbitration, but the record is easier to shape early than to correct later. Employer counsel represents the firm, and its interests may diverge from yours. FINRA can require registered persons to provide documents and testimony, and refusing has its own consequences. Knowingly giving false answers to investigators creates problems separate from the trading.
Before the interview or the response
Preserve your own messages and notes, including on personal devices used for work, and do not delete chats or apps once questions have begun. Keep your personal records, but let counsel handle access to firm files rather than copying them yourself. Research notes, models, and messages explaining why particular orders were entered often matter more than the trades themselves. We start by learning who has made the allegation, what period and products are involved, and whether a regulator is already involved. Then we work out whether to give an interview or a written explanation, and how, recognizing that no one can tell you at the outset how the firm or an agency will view it.