Haselkorn & Thibaut, P.A., operating as Investment Fraud Lawyers, reviews regulatory actions that can signal broader risks for investors. Sung Moo Cho, also known as Sam Cho, was barred by the Financial Industry Regulatory Authority (FINRA) in June 2026. He refused to produce documents FINRA requested while it investigated allegations that he misappropriated about $3.5 million from a customer account, forged signatures, and falsified firm records.
Cho first became registered with FINRA in 2006.
From January 2021 through October 2025, he worked as a General Securities Representative with Ameriprise Financial Services, LLC (CRD No. 6363). He then moved to Citigroup Global Markets Inc. (CRD No. 7059) from October 2025 through May 2026.
On May 13, 2026, Citigroup filed a Form U5 terminating Cho. The filing disclosed allegations that he removed customer personally identifiable information from firm systems. It also said he created a non-firm-generated statement that was provided to a client.
He also refused to cooperate with an internal investigation.
What FINRA alleged
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FINRA Rule 8210 gives FINRA staff authority to require persons under FINRA jurisdiction to provide information, documents, or testimony in connection with an investigation. Cho received two Rule 8210 request letters.
The first, dated May 15, 2026, set a June 1, 2026 deadline. The second, dated June 2, 2026, extended the deadline to June 16, 2026. Cho did not provide any requested information or documents by either deadline.
In an email from his counsel to FINRA dated June 10, 2026, Cho acknowledged receipt of the requests. He confirmed he would not produce them. By refusing to comply, FINRA found that Cho violated FINRA Rule 8210 and FINRA Rule 2010. Rule 2010 requires associated persons to observe high standards of commercial honor and just and equitable principles of trade in the conduct of their business.
The underlying customer complaint alleged that Cho misappropriated about $3.5 million from a customer’s brokerage accounts. FINRA’s investigation also examined whether Cho forged customer signatures and falsified firm documents while at Ameriprise and Citigroup.
Sanctions and effect
On June 18, 2026, Cho signed the Letter of Acceptance, Waiver, and Consent. FINRA accepted the AWC on June 25, 2026. The sanction is a bar from associating with any FINRA member in all capacities, effective on the date of FINRA’s notice of acceptance.
A FINRA bar also creates a statutory disqualification under Section 3(a)(39) of the Securities Exchange Act of 1934. During the bar, Cho may not be associated with a FINRA member in any capacity, including clerical or ministerial functions.
Why this matters for investors
Allegations of this nature carry signals that investors should understand. Misappropriation of customer funds, forged signatures, and falsified records can occur without an account statement immediately showing the damage.
Brokerage account statements are usually the primary record most investors review. A representative with access to firm systems can alter or create documents that obscure activity.
Several warning signs can help investors detect problems early:
- Unauthorized withdrawals or transfers, especially when the receiving account is unfamiliar
- Checks or wires drawn from the account that the investor did not authorize
- Altered account statements, missing statement periods, or documents that do not match online records
- Requests to sign blank forms, or pressure to sign documents without time to review them
- Representatives who discourage direct contact with the firm’s main office or compliance department
- Difficulty obtaining original firm statements or trade confirmations
When a representative changes firms, investors should pay close attention to account activity. They should also confirm that the new firm has accurate records. In Cho’s case, the issue may have continued after the move.
What investors can do now
Investors who worked with Sung Moo Cho, or Sam Cho, while he was at Ameriprise or Citigroup should review their account history carefully. The key records include original account statements, trade confirmations, withdrawal and transfer records, check images, wire instructions, and any signed authorization forms.
Comparing records held by the broker-dealer against statements received directly from banks or other linked accounts can reveal discrepancies.
Investors who believe they suffered losses should consider these steps:
- Preserve all original account statements and correspondence in both paper and electronic form.
- Request a complete transaction history directly from the firm, not only from the representative.
- Compare the firm’s records against independent bank records.
- Document any oral instructions and the dates they were given.
- Consult a securities attorney before signing any release or accepting a goodwill payment from the firm.
Legal framework for recovery
FINRA Rule 8210 is a core enforcement tool. When a representative refuses to cooperate, FINRA cannot complete its fact-finding. The public cannot know the full scope of the misconduct.
The bar here is not a civil judgment. It does not establish that Cho committed the underlying acts. It does, however, prevent him from working in the securities industry while the bar is in effect.
Recovery for investors usually proceeds through FINRA arbitration rather than court. Brokerage customer agreements typically contain mandatory arbitration clauses. FINRA arbitration can address claims against the individual representative and, importantly, against the member firm that employed or supervised him. Firms can be held liable for negligent supervision, failure to detect red flags, or inadequate compliance procedures.
Key facts in the Sung Moo Cho FINRA action
| Fact | Detail |
|---|---|
| Respondent | Sung Moo Cho, also known as Sam Cho |
| CRD number | 5015906 |
| Firms | Ameriprise Financial Services, LLC (Jan. 2021–Oct. 2025); Citigroup Global Markets Inc. (Oct. 2025–May 2026) |
| Alleged customer harm | Misappropriation of about $3.5 million from a customer’s brokerage accounts |
| Additional allegations | Forgery of customer signatures and falsification of firm documents |
| Rule violations | FINRA Rule 8210 and FINRA Rule 2010 |
| Sanction | Bar from associating with any FINRA member in all capacities |
| AWC signed | June 18, 2026 |
| FINRA acceptance | June 25, 2026 |
Red flags for unauthorized account activity
| Warning sign | What to look for |
|---|---|
| Unauthorized withdrawals or transfers | Checks, wires, or ACH transfers the investor did not approve |
| Statement inconsistencies | Missing periods, altered figures, or statements that do not match online records |
| Signature issues | Documents with signatures the investor does not recognize or cannot remember signing |
| Representative resistance | Pressure to avoid firm compliance staff or delay official record requests |
| Firm changes | Activity problems that continue or begin after the representative changes firms |
How we can help
Haselkorn & Thibaut, P.A., operating as Investment Fraud Lawyers, represents investors who have lost money because of broker misconduct, unsuitable recommendations, and unauthorized account activity. We have been involved in over $520 million of securities cases, with a 98% success rate. We work on a contingency basis: no recovery, no fee.
If you believe you were affected by Sung Moo Cho or Sam Cho while he was registered with Ameriprise or Citigroup, call us at 1-888-885-7162 or visit InvestmentFraudLawyers.com to request a case review.
About Haselkorn & Thibaut, P.A.
Haselkorn & Thibaut, P.A., operating as Investment Fraud Lawyers, is a securities arbitration and investment fraud law firm. The partners are former Wall Street defense attorneys who now represent individual investors. The firm has received a Martindale-Hubbell AV Preeminent peer rating and has been recognized among the Top 2% of attorneys nationwide.
Jason S. Haselkorn is licensed in Florida, Bar No. 52140.
Matthew R. Thibaut is licensed in Florida, Bar No. 514918.
Disclaimer
This article reports publicly available regulatory information. It is not legal advice and does not create an attorney-client relationship. Past results do not guarantee future outcomes. Every case depends on its own facts.
Haselkorn & Thibaut, P.A. investigates FINRA broker-dealer and investment-adviser conduct to help investors understand their rights and recovery options.
