FINRA Rules Applicable to Digital Security Trading

FINRA, as the self-regulatory organization overseeing all SEC-registered broker-dealers, applies its extensive rulebook to digital security trading activities. According to FINRA’s ATS equity firms list, approximately two dozen firms have approved digital asset business lines with roughly two dozen more applications pending. Every ATS platform operating in the security token space — including tZERO (which launched near-24/7 trading in December 2025 and received FINRA approval to act as retailer of tokenized mutual funds), Securitize Markets ($4 billion+ in tokenized AUM), and INX (acquired by Republic for $60 million in April 2025) — must comply with FINRA rules as a condition of membership. Understanding which rules apply, and how they translate to blockchain-based trading, is essential for broker-dealers facilitating tokenized securities transactions.

Regulation Best Interest (Reg BI) and Suitability

FINRA Rule 2111 (Suitability), now aligned with the SEC’s Regulation Best Interest framework, requires broker-dealers to have a reasonable basis for believing that any recommended security token is suitable for the customer based on the customer’s investment profile, risk tolerance, liquidity needs, and financial situation.

For security tokens, suitability analysis must consider factors unique to tokenized securities:

• Liquidity risk. Security tokens trade with significantly lower liquidity than traditional equities. Average daily volume per token is $42K (vs. $280M for S&P 500 stocks), and market-making participation is limited. Broker-dealers must assess whether the customer can tolerate potential difficulty exiting positions.
• Rule 144 restrictions. Reg D tokens are restricted securities subject to holding periods. Customers must understand that tokens cannot be resold for 6-12 months after purchase, regardless of price movements.
• Technology risk. Smart contract vulnerabilities, blockchain network disruptions, and custody key management risks are unique to digital securities. Suitability analysis must evaluate the customer’s understanding of these technology-specific risks.
• Accreditation requirements. For Reg D tokens, broker-dealers must verify that customers meet accredited investor standards through approved verification methods.

Best Execution (Rule 5310)

FINRA Rule 5310 requires broker-dealers to use “reasonable diligence” to ascertain the best market for a security and execute customer orders at the most favorable terms reasonably available. In the security token market, best execution analysis presents unique challenges:

Fragmented venues. With 47 registered ATS platforms, security token liquidity is fragmented across multiple venues. However, most individual tokens are listed on only one or two platforms, limiting the opportunity for cross-venue price comparison.

Spread analysis. Average bid-ask spreads of 2.1% for security tokens are 100x wider than traditional equity spreads. Broker-dealers must document their best execution analysis, demonstrating that they considered available quotes, market depth, and execution probability.

Atomic settlement impact. The T+0 settlement capability of security tokens eliminates the settlement risk component of execution quality analysis. This structural advantage should be reflected in best execution documentation.

Trade Reporting Requirements

FINRA’s trade reporting requirements apply to all security token transactions executed by member firms:

TRACE/ATS reporting. Security token trades must be reported through the applicable FINRA reporting system. Non-NMS securities (which includes most security tokens) follow reporting requirements under FINRA Rule 6730 (Transaction Reporting).

ATS transparency data. ATS operators must report aggregate trading data to FINRA, which publishes quarterly ATS transparency reports. This data feeds our ATS market activity tracker.

Customer confirmations. Rule 10b-10 requires broker-dealers to provide written confirmations to customers for each security token transaction, including the price, quantity, commission, and ATS identification.

Anti-Money Laundering (FINRA Rule 3310)

All FINRA member firms must implement AML compliance programs that address the specific risks of digital security transactions:

Customer identification. Blockchain-based transactions require linking on-chain wallet addresses to verified customer identities. FINRA expects member firms to maintain a complete mapping between customer accounts, KYC records, and blockchain wallet addresses.

Suspicious activity monitoring. Firms must monitor for suspicious patterns in security token trading, including unusual volume spikes, rapid accumulation by unknown wallets, and transactions that may indicate wash trading or market manipulation.

Blockchain analytics. Leading security token platforms integrate blockchain analytics tools (Chainalysis, Elliptic) into their AML programs, enabling automated monitoring of wallet addresses against sanctions lists, darknet market indicators, and other risk signals.

Supervision Requirements (FINRA Rule 3110)

FINRA Rule 3110 requires member firms to establish and maintain written supervisory procedures (WSPs) for each type of business in which the firm engages. For security token activities, WSPs must address:

• Digital asset-specific training for registered representatives and compliance personnel.
• Smart contract review procedures for verifying that tokens listed on the firm’s ATS comply with applicable regulations.
• Cybersecurity supervision for blockchain node infrastructure, wallet key management, and API security.
• Token listing due diligence procedures for evaluating whether tokens satisfy the Howey test and are properly structured under an offering exemption.

Communications with the Public (FINRA Rule 2210)

All marketing communications for security token offerings and ATS trading must comply with FINRA Rule 2210, which requires:

• Fair and balanced presentation. Marketing materials must present both potential benefits and material risks of security token investments.
• Prohibition on misleading statements. Claims about token performance, liquidity, or regulatory status must be accurate and substantiated.
• Pre-use filing. Certain communications (including advertisements for Reg D 506(c) offerings using general solicitation) must be filed with FINRA’s Advertising Regulation Department within 10 business days of first use.
• Social media compliance. Digital marketing, social media posts, and Discord/Telegram announcements promoting security tokens must comply with the same standards as traditional advertisements.

Margin and Net Capital Requirements

FINRA margin rules and SEC net capital requirements apply to broker-dealers holding security token positions:

Net capital. Broker-dealers operating ATS platforms must maintain minimum net capital of $250,000 under SEC Rule 15c3-1. Firms holding customer security tokens must apply appropriate haircuts to proprietary token positions in their net capital calculations.

Customer margin. FINRA Rule 4210 governs margin for non-exempt securities. Security tokens purchased on margin (where available) are subject to the same initial and maintenance margin requirements as traditional securities — typically 50% initial margin and 25% maintenance margin.

Examination Priorities for Digital Securities Firms

FINRA publishes annual examination priorities that increasingly address digital security activities. Key examination focus areas for 2025-2026 include:

New member applications. FINRA has heightened scrutiny for new member applications from firms proposing digital asset activities. The Membership Application Program (MAP) reviews evaluate the firm’s technology infrastructure, compliance staffing, cybersecurity capabilities, and understanding of Howey test classification requirements. Application review timelines for digital asset firms average 8-12 months — significantly longer than the 4-6 month average for traditional broker-dealer applications.

Continuing membership applications. Existing FINRA members seeking to add digital asset activities must file a Continuing Membership Application (CMA). The CMA process evaluates whether the firm has adequate supervisory systems, compliance personnel, and technology infrastructure to support the new business line. Firms adding ATS operations for security tokens face particularly detailed review of their Form ATS-N disclosures and settlement architecture.

Crypto asset-related communications. FINRA has increased review of marketing materials and social media communications related to digital securities. The Advertising Regulation Department has issued multiple deficiency letters to firms for misleading social media posts about security token offerings, particularly posts that emphasize potential returns without adequate risk disclosure.

FINRA Regulatory Notices Relevant to Digital Securities

Several FINRA Regulatory Notices specifically address digital asset activities:

Regulatory Notice 19-24 (July 2019). FINRA requested comment on how existing rules apply to digital asset securities, signaling its intention to provide clearer guidance. The notice identified custody, AML, supervision, and net capital as areas requiring digital asset-specific guidance.

Regulatory Notice 21-25 (June 2021). FINRA reminded member firms of their obligation to report all digital asset security transactions and maintain adequate supervisory procedures for digital asset activities. The notice specifically addressed the growing use of DeFi protocols by broker-dealer affiliates.

FINRA Exam Findings Reports. FINRA’s annual examination findings reports have identified common deficiencies at firms with digital asset activities, including inadequate technology risk assessments, insufficient documentation of accredited investor verification, and failure to implement blockchain-specific AML monitoring procedures.

Dispute Resolution

FINRA’s dispute resolution forum handles customer complaints related to digital security transactions:

Customer complaints. Investors who believe a broker-dealer violated FINRA rules in connection with a security token transaction can file a complaint through FINRA’s Investor Complaint Center. Common complaints include failure to disclose liquidity restrictions, inadequate suitability analysis, and unauthorized transactions.

Arbitration. FINRA mandates arbitration for disputes between customers and member firms. Security token disputes have appeared in FINRA arbitration proceedings, with cases addressing issues including platform outages during trading windows, custody losses due to key management failures, and misrepresentations about token liquidity. As the secondary market for Reg D and Reg A+ security tokens grows, FINRA anticipates an increase in arbitration filings related to digital securities, particularly around Rule 144 holding period disputes and token liquidity representations made during the offering process.

FINRA and the Evolving Digital Securities Landscape

FINRA’s approach to digital securities regulation continues to evolve alongside the SEC’s Crypto Task Force policy development. The Task Force conducted six roundtables through Q1 2026 — including the April 11, 2025 session “Between a Block and a Hard Place: Tailoring Regulation for Crypto Trading” that directly addressed FINRA’s role in overseeing digital asset trading platforms.

Key FINRA Developments in 2025-2026

tZERO FINRA approvals. In December 2025, tZERO received FINRA approval to act as a retailer of tokenized mutual funds, expanding the types of digital securities that FINRA-regulated broker-dealers can distribute. tZERO simultaneously launched near-24/7 trading (23.5 hours per day), requiring FINRA to evaluate supervisory procedures for extended-hours digital securities trading — a first for the self-regulatory organization.

Agora ATS-to-ATS connector. The January 2026 launch of Agora by tZERO and North Capital — the first ATS-to-ATS connector for tokenized securities — raises FINRA compliance questions about cross-platform trade execution, best execution obligations when orders can route between ATSs, and supervisory responsibility allocation between the originating and executing platforms.

Republic-INX integration. Republic’s April 2025 acquisition of INX for $60 million created a combined entity with both FINRA-registered broker-dealer and ATS operations, requiring FINRA review of the combined supervisory structure and potential conflicts between Republic’s primary issuance platform and INX’s secondary trading venue.

Prometheum subsidiary expansion. Prometheum’s expansion to include Prometheum Coinery LLC (digital transfer agent, registered May 2025) and ProFinancial Inc. (capital formation, acquired May 2025) created the most vertically integrated FINRA-supervised digital securities operation, requiring comprehensive supervisory procedures covering issuance, custody, transfer agent services, and ATS trading within a single FINRA member firm structure.

FINRA Examination Trends

FINRA’s 2025-2026 examination program has prioritized several areas specific to digital securities firms:

Cybersecurity and key management. FINRA examiners have increased scrutiny of private key management procedures, HSM configurations, and multi-signature wallet governance at broker-dealers custodying digital asset securities. Firms that operate SPBD custody face enhanced examination cycles with quarterly reporting requirements to both the SEC and FINRA.

Smart contract compliance verification. Examiners now routinely request documentation of smart contract audit results, transfer restriction enforcement testing, and the process for updating compliance parameters in token smart contracts. The SEC’s April 10, 2025 staff guidance requiring smart contract code as a filing exhibit has given FINRA examiners a formal basis for reviewing smart contract architecture during examinations.

AML monitoring for blockchain transactions. FINRA has increased expectations for blockchain-specific AML monitoring, requiring member firms to demonstrate that their AML programs include wallet screening against OFAC sanctions lists, analysis of token flow patterns for suspicious activity, and integration of blockchain analytics tools (Chainalysis, Elliptic, TRM Labs) into their transaction monitoring infrastructure.

Market manipulation detection. With security token markets characterized by thin trading volumes and wide spreads, FINRA has heightened surveillance for wash trading, spoofing, and layering in digital securities. Member firms must demonstrate that their surveillance systems can detect manipulation patterns in blockchain-based trading that may differ from traditional equity market manipulation techniques.

FINRA Net Capital Treatment for Digital Securities

FINRA’s application of SEC Rule 15c3-1 (Net Capital Rule) to digital securities positions requires broker-dealers to apply appropriate haircuts that reflect the volatility and liquidity characteristics of security tokens:

These haircut levels directly affect the economics of digital securities broker-dealer operations, as higher haircuts require more net capital to support the same level of business activity. Firms like Securitize Markets, tZERO, and INX must maintain net capital levels that account for both their ATS operations and any proprietary token positions.

For the ATS platform comparison analyzing FINRA compliance across platforms, see our comparisons section. For broker-dealer requirements that intersect with FINRA membership obligations, see our guide. For the SEC enforcement tracker documenting FINRA-referred cases, see our dashboards. For FINRA’s official digital asset guidance, see FINRA’s Digital Assets Topic Page.