CAT Fee 2026-1 adds audit-trail costs for brokers; options traders may see higher pass-through fees

The Consolidated Audit Trail (CAT) is an infrastructure project that records the lifecycle of U.S. equities and options orders for regulatory oversight. New CAT billing updates for 2026 are now in SEC-published filings, and they can translate into small but real execution-cost friction for active options traders.

The most important takeaway is scale: CAT Fee 2026-1 is measured in millionths of a dollar per executed equivalent share. For most traders, it is not a “volatility catalyst.” It is a transaction-cost detail that matters primarily when your strategy turns over a lot of contracts and a lot of legs.

This article is for market context and options education only. It is not financial advice, investment advice, trading advice, or a trade recommendation. Options trading involves risk and is not suitable for all investors.

Why This Matters For Options Traders

CAT Fee 2026-1 is a market-structure update that can show up as a small per-trade cost. It is most relevant when your strategy relies on tight execution (spreads) or repeated turnover (many trades, many legs, frequent adjustments). It is not a directional signal and it does not change how options settle or how assignment works.

The Key Numbers (In Plain English)

SEC Release No. 34-105478 (Nasdaq MRX) describes CAT Fee 2026-1 as $0.000001 per executed equivalent share, invoiced monthly to industry members, with the first invoice in June 2026 based on May 2026 activity.

For listed options, CAT uses the contract multiplier to translate contracts into “executed equivalent shares.” For a standard U.S. listed option contract, that multiplier is typically 100, so the prospective CAT Fee 2026-1 alone works out to approximately:

• $0.000001 × 100 = $0.0001 per options contract per execution

That is one-hundredth of one cent per contract. It is economically tiny next to the usual per-contract charges options traders already see (commissions, the Options Regulatory Fee, and clearing-related fees).

The nuance is that CAT Fee 2026-1 is not necessarily the whole 2026 story. The same wave of CAT documents also establishes a separate Historical CAT Assessment 1A at $0.000002 per executed equivalent share, starting on the same invoice schedule. If a broker passes both through mechanically, the combined math for a standard options contract is:

• ($0.000001 + $0.000002) × 100 = $0.0003 per options contract per execution

At least one retail broker already discloses a per-contract “CAT” line item that matches this combined calculation, which is a practical reminder that upstream market-structure costs can show up on your fee schedule even when they are billed to brokers first.

What Is CAT (In One Paragraph)

CAT is a consolidated regulatory database for order and execution records across U.S. equities and listed options. It exists to help regulators reconstruct market events and monitor for issues like manipulation, abusive trading practices, and systemic problems. Funding CAT requires ongoing fees, and those fees are set through the CAT NMS Plan process and then reflected in exchange and FINRA rule filings.

For options traders, CAT is not a new product and it does not change option contract rights or exercise rules. It is an execution-cost input.

When Traders Might Notice It

Traders generally will not “see CAT” in the options chain. If it shows up at all, it tends to show up in one of three places:

1. A new explicit line item on a broker’s pricing/fee disclosures (sometimes labeled as a CAT or FINRA-CAT fee).
2. A bundled increase in an “all-in regulatory/clearing” options fee.
3. A small deterioration in effective execution economics for strategies that already live or die on spread cost (especially many-leg and frequently adjusted positions).

How To Think About Impact Without Overstating It

It is easy to overreact to any new “fee headline.” Here is a disciplined way to frame it:

• Confirmed fact: CAT Fee 2026-1 and Historical CAT Assessment 1A are defined as executed-equivalent-share fees in SEC-posted rule filings and CAT fee alerts.
• Likely trader-level effect: Some brokers will pass these through explicitly or implicitly, so per-trade costs can rise slightly.
• Not confirmed: A broad, mechanical shift in implied volatility, skew, or expected move driven directly by CAT. Any such impact would be indirect and second-order, via how brokers and liquidity providers recover costs.

Where It Matters Most: Trade Count, Leg Count, And Strategy Turnover

The direct per-contract number is tiny, but it compounds with repetition and complexity. Examples (using the combined $0.0003-per-contract-per-execution figure as a reference point):

• A one-lot single-leg position opened and later closed is two executions: about $0.0006 of CAT pass-through on that round trip (if your broker passes through both components mechanically).
• A one-lot vertical spread opened and later closed is typically four contract executions (two legs, open and close): about $0.0012.
• A one-lot four-leg iron condor opened and later closed is typically eight contract executions: about $0.0024.

Those numbers are still small. The practical point is not that CAT will “break” retail options trading. The point is that active workflows (0DTE scalps, frequent rolling, multi-leg adjustment loops, high-volume premium systems) should be honest about small costs that recur often.

For readers who want a refresher on why transaction costs matter more than most backtests assume, start with Probability of Profit (POP) and common options trading mistakes.

What Traders May Misunderstand

• “This fee is big.” Per contract, it is typically a fraction of a cent; the more realistic risk is death-by-a-thousand-cuts in high-turnover strategies, not a single large hit.
• “This changes assignment risk.” CAT is an execution cost. It does not change exercise style, settlement, or OCC assignment mechanics.
• “This will move implied volatility.” A fee change is not a volatility forecast. If spreads or IV change, it would be an indirect consequence of pricing and routing behavior, not a direct mechanical repricing.
• “If I don’t see a CAT line item, I’m not paying it.” You might still be paying it implicitly if your broker bundles fees or recovers costs elsewhere.

Practical Checklist (No Trade Calls)

If you are an active options trader, these are reasonable next steps:

• Check your broker’s fee schedule for any “CAT” or “FINRA-CAT” options line item, and note whether it is per-contract or per-share.
• Spot-check trade confirmations for regulatory/clearing fee breakdowns on options executions.
• If you track performance, add a dedicated “execution costs” bucket that includes commissions, regulatory fees, clearing fees, and any CAT-related pass-through so your stats stay realistic.
• For multi-leg and high-turnover strategies, use limit orders and be intentional about how much spread you are paying; spread cost is usually still the dominant friction.

This article is for education and market commentary only. It is not financial advice, investment advice, or trading advice. Options trading involves risk and is not suitable for all investors.

Sources

• SEC Release No. 34-105478 (Nasdaq MRX CAT Fee 2026-1 filing): https://www.sec.gov/files/rules/sro/mrx/2026/34-105478.pdf (primary filing for fee rate, options mapping, and invoice schedule)
• SEC Release No. 34-105449 (FINRA CAT Fee 2026-1 filing): https://www.sec.gov/files/rules/sro/finra/2026/34-105449.pdf (cross-check on mechanics and billing approach)
• SEC Release No. 34-105470 (FINRA Historical CAT Assessment 1A filing): https://www.sec.gov/files/rules/sro/finra/2026/34-105470.pdf (historical assessment rate and context)
• CAT Fee Alert 2026-1: https://www.catnmsplan.com/sites/default/files/2026-04/04.01.26-CAT-Fee-Alert-2026-1.pdf (fee timing, invoice schedule, and CAT operator notice language)
• CAT Fee Alert 2026-2: https://www.catnmsplan.com/sites/default/files/2026-04/04.01.26-CAT-Fee-Alert-2026-2.pdf (historical assessment timing and line-item billing language)
• SEC Rule 613 / CAT overview page: https://www.sec.gov/about/divisions-offices/division-trading-markets/rule-613-consolidated-audit-trail (regulator explainer of CAT and Rule 613)
• Interactive Brokers options pricing disclosures: https://www.interactivebrokers.com/en/pricing/commissions-options.php (example retail-facing fee schedule that includes a CAT-related per-contract line item)