Two Years to Rule 10c-1a and SLATE: Preparing for the Baseline While Awaiting the Reproposal

On December 3, 2025, the Securities and Exchange Commission granted a further temporary exemption from compliance with Rule 10c-1a. Covered persons need not report securities-loan information to a registered national securities association (RNSA) until September 28, 2028. The association need not make the prescribed information public until March 29, 2029. The rule has been in effect since January 2, 2024, and the exemption shifts the calendar but does not reopen the fields.

With two years remaining until reporting commences and two and a half years until public dissemination, FINRA, the sole RNSA, has adopted the Rule 6500 Series and established SLATE (Securities Lending and Transparency Engine) as the platform for report submissions. According to the FINRA manual, Rule 6530 (governing reporting) is slated to take effect on September 28, 2028, followed by Rule 6540 (governing dissemination) on March 29, 2029. While FINRA anticipates updating its documentation prior to launch, it is currently holding to the participant specification dated June 27, 2025. Schedules for customer test environments and firm onboarding have yet to be established.

Yet treating FINRA’s published parameters as a permanent, settled blueprint is precipitous. The SEC’s current RegFlex agenda (RIN 3235-AN73) explicitly targets Rule 10c-1a for proposed amendments slated for 2027. What ultimately must be reported and what FINRA ultimately disseminates are almost certain to change. Market participants should not read the current specification as a finished mandate, but as an operational baseline: the structural starting point firms must prepare for, even as the SEC’s impending reproposal prepares to shift the ground beneath it.

The calendar, and why it moved

Under the original October 13, 2023 adopting release, reporting was scheduled to begin twenty-four months following effectiveness (January 2, 2026), with public dissemination following ninety days later (April 2, 2026). The Commission subsequently approved FINRA’s proposed Rule 6500 Series, as modified by Partial Amendment No. 1, on January 2, 2025.

Implementation was delayed through two subsequent orders. First, Release 34-103560 (July 28, 2025) shifted reporting to September 28, 2026, and dissemination to March 29, 2027, granting FINRA additional time to construct and test the facility. Later, Release 34-104303 (December 3, 2025) pushed both timelines back by an additional two years. This second extension responded to the Fifth Circuit’s August 25, 2025 remand without vacatur, which instructed the SEC to analyze and quantify the combined economic impact of Rule 10c-1a and Rule 13f-2.

The Commission noted that the exemption provided time in which it might propose amendments. Under RIN 3235-AN73, the Commission has formalized that timetable for 2027. While no amending release has altered the data elements to date, the current specification must be understood as an interim benchmark rather than a final commercial standard. A reader of the October 2023 note, or of the February 2025 note, should treat the baseline specification below as the current operational architecture, subject to revision as the Commission responds to the judicial remand.

What is reported, and to whom

Within this baseline architecture, a covered securities loan occurs when any party, acting on its own behalf or on behalf of others, lends a reportable security to another entity. The designation of covered person applies to the intermediary arranging the loan for the lender, or to the lender itself if no intermediary participates. Additionally, when a broker-dealer borrows fully paid or excess margin securities from a customer pursuant to Rule 15c3-3(b)(3), the broker-dealer is deemed the covered person rather than the customer. Central securities depositories and central counterparties operating exclusively in those capacities are not treated as covered persons, meaning any resulting clearing agency positions are excluded from covered securities loan status.

A security qualifies as a reportable security if it or any class of its issuer’s securities is subject to reporting requirements under the Consolidated Audit Trail (CAT), FINRA’s Trade Reporting and Compliance Engine (TRACE), the Municipal Securities Rulemaking Board’s Real-Time Transaction Reporting System (RTRS), or any successor system. Classification depends strictly on the underlying security rather than the settlement mechanism used. As clarified in the Rule 10c-1a adopting release, the reporting obligation is triggered upon agreement to the loan terms prior to settlement; settlement methods such as delivery versus payment, free of payment, or the involvement of a clearing corporation do not alter this determination.

Under that definition, a loan of a listed equity, an over-the-counter equity, an exchange-traded fund share, a listed blank-check common, or a listed option is within the CAT universe and reportable if it is a loan of that instrument. A loan of a U.S.-dollar TRACE-eligible convertible note is reportable in par. A convertible preferred that is itself a CAT equity is reportable in shares. A loan of a futures contract, a security future, or a swap is not a loan of a CAT, TRACE, or RTRS security, and is outside the rule. A stock loan that hedges or settles one of those contracts is tested on the stock, not on the derivative. Repurchase agreements are not covered securities loans. A broker-dealer’s use of margin securities is not a covered securities loan unless the broker-dealer lends those securities on to another person. Money-market instruments excluded from TRACE, non-dollar debt, and municipal fund securities excepted from RTRS are outside the definition.

SLATE reporting deadlines depend on transaction timing: loans agreed between midnight and 7:00 p.m. Eastern Time on a business day must be submitted by 11:59:59 p.m. that same day, whereas transactions executed after 7:00 p.m. or during non-business days are due on the following business day. For securities subject to the Consolidated Audit Trail (CAT), volume is measured in shares, while securities under TRACE or RTRS reporting are measured by par value. When a rate is structured as a spread, reporting must capture the effective date, the spread value, and the underlying benchmark.

Three public resources

FINRA’s Rule 6540 provides access to three distinct public resources, none of which contain confidential details. Market participants are tracked using FINRA-assigned unique public keys rather than internal firm identifiers, and client-level loan IDs remain undisclosed per the participant specification. Together, these datasets serve as foundational inputs for evaluating current market conditions rather than predictive forecasts:

• Loan terms: Morning after the report is accepted. Includes identifier, security, collateral type, rebate or fee, collateral percentage, termination date, venue, and borrower category. Not size. Not a name.
• Loan amount: Twentieth business day after effect, or after a modification of amount. Includes size, joined on the FINRA identifier to the term record. A lagged measure of the loan, not of the book.
• Daily statistics: Morning after the report. Aggregate volume only if ten or more distinct identifiers printed. High, low, and volume-weighted average rate, with no ten-loan gate.

Viewed as an indicator of market conditions, the three public datasets classify any given security into one of three distinct statuses:

1. Active & Transparent Session: A security printing ten or more unique identifiers alongside a rate distribution and aggregate volume denotes active, visible new lending or resizing during that trading day.
2. Active but Opaque Volume: A security printing a rate distribution without aggregate volume successfully cleared the rate statistic but failed the ten-loan threshold. While trading activity took place, its total volume remains obscured loan-by-loan until the twentieth business day.
3. Unreported / Unmodified Status: A security with no printed data reflects either complete inactivity or an existing portfolio of open loans that experienced no modifications—a distinction the reporting file itself cannot resolve.

Term records are conditioned on several key variables: collateral type, rebate currency, collateral percentage, termination date, venue, and borrower classification (which encompasses broker-dealers, customers, clearing agencies, banks, custodians, or other entities). While the volume-weighted average offers a functional benchmark, the high and low metrics reflect market dispersion and remain subject to noise when trading volume is light. Once reported, loan size serves to weight the transaction, though it cannot account for unrecorded loans.

The morning release aggregates transactions accepted during the preceding business day. While the regulation prescribes publication “no later than the morning of the next business day,” it does not specify a precise deadline. A transaction executed at 11:00 a.m. falls within the same-day reporting timeframe; if accepted that evening, it becomes eligible for inclusion in the subsequent morning’s term file, excluding loan size. The public file functions neither as an operational blotter nor as a real-time intraday record.

What is collected and not published

The confidential block, reported under Rule 10c-1a(e) and Rule 6530(a)(2)(M) through (U), is not disseminated. It includes the covered person’s market-participant identifier, if known; the legal name of each party, other than the customer on a Rule 15c3-3(b)(3) borrow, whose name is not reported at all; each party’s CRD or IARD number, market-participant identifier, and legal-entity identifier, if known; whether each party is lender, borrower, or intermediary; whether a broker-dealer is lending from its own inventory to its customer; and whether the loan is being used to close out a fail under Regulation SHO Rule 204, or a fail outside that rule. The field in the adopted rule and in the FINRA series is the close-out flag, not a statement of purpose under Regulation T.

Disseminated data can be accessed free of charge on FINRA’s website for personal, non-commercial purposes pursuant to Rule 6540.02. That provision likewise authorizes FINRA to charge Commission-filed fees for data distribution. Specifically, Rule 7720 sets the monthly commercial file fee for daily statistics and loan-level data at $3,000 (with an exception for qualifying tax-exempt entities) and establishes a $10,000 monthly vendor display-redistribution fee, while strictly prohibiting bulk redistribution.

There is no opening book

Under Rule 10c-1a(d)(2), loans finalized prior to the reporting date do not require submission as new loans. A pre-existing covered securities loan is introduced to the tape only upon its first post-reporting-date modification, provided that modification alters a reportable data element. At that point, the covered person must report all paragraph (c) elements reflecting the modification date. FINRA executes this requirement as a pre-existing loan modification event: post-launch rate adjustments, quantity changes, or terminations are reportable, whereas the initial loan agreement is not. FINRA assigns the loan identifier upon the occurrence of that reportable event.

A market-state series built from these resources starts empty of legacy loans and fills only as old loans are touched. The first public observation of a legacy loan is the modification snapshot, not the original agreement, although the snapshot includes the original effective date and time among the reported elements. Size on that loan follows the modification: the twentieth business day after the change that brought the loan onto the tape.

A limited use for principal lenders and borrowers

The public tape serves as a benchmark for comparison rather than a tool for full portfolio reconstruction. Principal borrowers and lenders can evaluate their individual rebates or fees against the published high, low, and volume-weighted average metrics for a given security. These comparisons are categorized by collateral type (cash versus non-cash) and, for rebates, by currency, becoming accessible the morning after a transaction is accepted. Conversely, loan-level size data is delayed by twenty business days. Aggregate daily volume is published the following morning exclusively for securities clearing with at least ten unique loan identifiers; a security displaying rate distributions without aggregate volume indicates thin trading activity rather than omitted data.

Beyond these baseline figures, a principal participant remains blind to counterparties and intermediaries. Loans that were already active on the reporting date and remain untouched thereafter will stay invisible. Furthermore, the public file offers no insight into overall availability, total shares on loan as a stock position, or returns not logged as modifications. Nor does it surface repurchases, swaps, or futures hedges. These boundaries are fixed by the rule itself, defining the strict limits of what public disclosures will reveal—both two years from the reporting start and two and a half years from publication.

Preparing for the baseline amid regulatory limbo

Securities finance desks and technology providers cannot afford to ignore this architecture, but neither can they afford to treat it as immutable. Building ingestion engines and compliance workflows to match the June 2025 FINRA specification represents sound risk management for the September 2028 deadline. However, hardcoding operational models exclusively to these fields creates significant technical exposure.

The Commission’s forthcoming 2027 reproposal under RIN 3235-AN73 will re-evaluate the cumulative economic burdens mandated by the Fifth Circuit remand. Elements such as the twenty-day size delay, the definition of covered intermediaries, or the threshold for aggregate volume dissemination could be meaningfully modified.

Until an amending release is formally proposed and adopted, the operative legal specification remains Rule 10c-1a(g), FINRA Rule 6540, and the data-element list in Rule 6530. Industry participants must build to this baseline while maintaining the architectural flexibility required as regulatory parameters inevitably shift.