OpenChainGraph Suite · ART-580 · Capital Markets · Broker-Dealer Reserve Formula

15c3-3a Note H Margin-Debit Computation

Recomputes whether a margin debit tied to a broker-dealer's customer U.S. Treasury positions delivered to a registered clearing agency qualifies for inclusion in the Rule 15c3-3 customer or PAB reserve formula under Note H to Exhibit A (Rule 15c3-3a). Note H permits that one debit line only once the clearing agency's rules satisfy several Commission-approved conditions and the margin itself comes from a permitted source. Each condition is checked here as its own declared boolean, cited to the specific Note H subsection it comes from, and the verdict is INCLUDABLE, NOT_INCLUDABLE or INDETERMINATE. Where INCLUDABLE, the debit is the smaller of the margin required and the margin actually on deposit. This is a narrow sibling to the shipped ART-396 15c3-3 reserve tool: it recomputes only the Note H sliver, never the full Items 1-14 formula, and never edits that tool.

Condition-by-condition, cited Sibling to ART-396, not a replacement Fixed-point money math Not legal or regulatory advice

Basis: Exchange Act Rule 15c3-3a Note H(b)(1)-(3) · SEC Treasury-clearing compliance dates: cash by 2026-12-31, repo by 2027-06-30

🔒 All inputs are processed locally in your browser. No data is transmitted. Do not enter real personal data — use synthetic or anonymised inputs only.

⚠ This is not legal or regulatory advice. It recomputes only the Note H margin-debit sliver, not the full Rule 15c3-3a reserve formula (Items 1-14, see ART-396 for that). Whether a clearing agency's rules and Commission notice actually satisfy Note H, and whether the declared facts are accurate, is for the broker-dealer's own compliance and financial-operations review. This page computes once when you press the button, stores nothing, runs on no schedule, and retains nothing.

Broker-dealer and clearing agency

The demo figures below are synthetic. They are not a copy of any real firm's reserve computation, and they are already loaded so you can press Run without entering anything of your own.

Broker-dealer reference

Computation date (your input, never a clock read)

Currency

Clearing agency name

Note H clearing-agency conditions (each a declared boolean)

JSON object: commission_notice_published, commission_notice_dated, per_customer_gross_margin_calc, cash_investment_short_term_treasuries_only, special_clearing_account_designated, excess_margin_return_system. Omit a key (or use null) to leave it unstated, which forces INDETERMINATE rather than a guess.

Margin source (Note H(b)(1))

Source

Customer lacked sufficient assets (narrow path only)

Margin recouped by next business day (narrow path only)

Margin amounts

Margin required, minor units

Margin on deposit, minor units (leave blank for INDETERMINATE)

Note H conditions

Rejected inputs

Rationale

Execution Hash (SHA-256)

What this does not do

It does not recompute Items 1-14 of the Rule 15c3-3a customer or PAB reserve formula, only the Note H margin-debit sliver (see ART-396 for the full formula). It does not verify a clearing agency's rulebook or a Commission notice against the Federal Register at run time; both are caller-declared facts. It is not legal or regulatory advice, and it makes no assertion about whether any clearing agency's actual rules satisfy Note H.

Sibling to ART-396 15c3-3 Reserve Formula Computation, which recomputes the full Items 1-14 customer/PAB reserve formula. This tool is independent and narrower: it covers only the Note H margin-debit condition checks and amount, never the rest of the formula, and it never edits ART-396.