On May 29, 2026, Cboe filed SR-CBOE-2026-051 proposing a new transaction-fee structure for two bitcoin-linked index option products: CBTX (Cboe Bitcoin U.S. ETF Index options) and MBTX (the mini version).
Instead of a mostly flat electronic fee schedule for non-customers, the filing introduces a maker-taker model: higher fees for non-customer orders that remove liquidity and new rebates for registered market makers that add liquidity. Cboe argues the goal is to reduce adverse selection (getting “picked off” on stale quotes) and support tighter, more stable markets in high-volatility products.
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Executive Summary
- What changed: A maker-taker schedule is proposed for CBTX and MBTX options, with new market-maker rebates for adding liquidity and higher non-customer fees for removing liquidity.
- Who it targets: The fee asymmetry mainly affects non-customer, electronic trading activity (including professional and firm flow). Customer rates are unchanged in the filing summary.
- Why it matters: If market makers face less “quote sniping” pressure and receive rebates for posted liquidity, quoted spreads can tighten and displayed size can improve, especially in short-dated series where hedging is fast.
- What it is not: This is a market-structure change, not a directional signal for bitcoin or bitcoin ETF prices.
What are CBTX and MBTX (in one minute)
CBTX and MBTX are cash-settled index options based on a bitcoin U.S. ETF index (a benchmark tied to a basket of U.S.-listed spot bitcoin ETFs). They are European-style index options, which means no early exercise and no ETF-share delivery at expiration. If you want a refresher on these mechanics:
MBTX is designed to be a smaller-size version of CBTX (a “mini” index option), which can matter when fixed per-contract fees are a large percentage of the premium you are trading.
The proposal: maker rebates + taker fees
The filing frames the change as a response to adverse selection in fast markets. In plain English:
- If you “take” liquidity (hit a bid or lift an offer) as a non-customer in certain situations, the per-contract fee goes up.
- If you are a registered market maker and you “make” liquidity (post a quote/order that gets lifted) in certain situations, you can receive a per-contract rebate.
Below is the high-level electronic schedule described in the filing for key fee codes (simplified summary; exact applicability depends on participant capacity and whether the contra side is a customer or non-customer):
| Product | Customer (electronic) | Non-customer removing liquidity (contra non-customer) | Market maker adding liquidity (contra non-customer) | Non-customer adding liquidity (certain cases) |
|---|---|---|---|---|
| CBTX | $0.50 (B1) | $1.50 (B3) | ($0.75) rebate (B4) | $1.00 (B5) |
| MBTX | $0.25 (M1) | $1.00 (M3) | ($0.50) rebate (M4) | $0.50 (M5) |
How a maker-taker model can affect spreads (and why Cboe thinks it helps)
Crypto-linked options can move quickly, and market makers often hedge across correlated instruments (e.g., underlying ETFs, futures, or other derivatives). When prices jump, a market maker’s posted quote can become stale before it is updated, creating “pick-off” risk.
Cboe’s argument is that fees can change the economics of that environment:
- A higher taker fee raises the all-in cost to execute small-edge, high-speed “sniping” strategies that rely on minimal transaction friction.
- A maker rebate subsidizes the cost of providing displayed liquidity, which can help market makers quote tighter or show more size (because the rebate can offset part of the expected adverse selection cost).
That is the theory. In practice, whether spreads tighten (and by how much) depends on what market makers do with the rebate and how much taker behavior changes once fees rise.
Why this matters for options traders
Most traders experience market structure as “execution quality”: the spread you pay, how often you get filled, and whether liquidity disappears when the tape gets fast.
Here are practical implications to watch, without assuming any particular outcome:
1) All-in trading costs can change materially in small-premium trades
Per-contract fees are fixed dollar amounts. In products where option premiums can be small relative to notional exposure, a fee change can be a meaningful portion of the total cost, especially when you trade multi-leg structures.
2) Spreads can tighten, but it may show up unevenly across strikes and expirations
If the fee change meaningfully reduces pick-off risk, you would most expect to see improvements in:
- Near-the-money, short-dated series (high gamma, frequent hedging).
- Periods with fast moves, where quote updates are hardest.
But liquidity can still be thin in deep OTM strikes or longer-dated expirations if natural interest is limited.
3) Customer accounts do not receive maker rebates
The rebate described in the filing applies to registered market makers meeting quoting obligations, not typical customer accounts. If spreads tighten, customer traders benefit indirectly through better quotes, not by collecting rebates.
4) Cash-settled, European-style index options change assignment/exercise mechanics
For traders used to ETF options, European exercise and cash settlement can reduce early-assignment mechanics and share-delivery considerations. That can simplify some risk management, but it does not remove risk: volatility, gap moves, and liquidity conditions still matter.
If you want a refresher on what drives option prices and how volatility shows up in premiums:
Common misunderstandings
- A maker-taker fee change does not guarantee tighter spreads. It changes incentives; the realized effect depends on participation, competition, and risk management in fast markets.
- Quoted spreads are only one part of execution. Fill probability, size, and how quotes behave during volatility spikes can matter more than the “average” day.
- Even if execution improves, these are still bitcoin-linked products. Fee mechanics do not remove gap risk, volatility risk, or liquidity risk.
What to watch after the change (execution-focused checklist)
If you trade or track CBTX/MBTX, the most useful post-change questions are execution questions:
- Do quoted spreads narrow in the most active expirations and strikes?
- Does displayed size improve during fast markets, or does it still vanish when volatility spikes?
- Do volume and open interest migrate toward (or away from) CBTX/MBTX relative to single-ETF options on major bitcoin ETFs?
- Do fills improve for limit orders near mid, or does the market still trade mostly at the bid/ask?
None of these are directional signals for bitcoin. They are checks on whether the market structure change translates into better (or worse) trading conditions.
Bottom line
SR-CBOE-2026-051 proposes to reprice liquidity in CBTX and MBTX options: pay more to remove it (in certain non-customer electronic scenarios) and pay market makers to provide it (in certain add-liquidity scenarios). If it works as intended, options traders may see tighter spreads and more reliable quotes in these bitcoin-linked index options. But the real test will be what shows up in post-change spreads, depth, and fill quality across the most traded expirations.
Sources
- Cboe Exchange, Inc., SR-CBOE-2026-051 (rule filing PDF; fee-code descriptions and “immediate effectiveness” language):
https://cdn.cboe.com/resources/regulation/rule_filings/approved/2026/SR-CBOE-2026-051.pdf - Cboe Options Exchange Fee Schedule (fee codes; reference for CBTX/MBTX electronic fee lines):
https://www.cboe.com/us/options/membership/fee_schedule/ - Cboe Bitcoin U.S. ETF Index Options Fact Sheet (product overview and specifications):
https://cdn.cboe.com/resources/membership/Cboe_Bitcoin_US_ETF_Index_Options_Fact_Sheet.pdf - Cboe Bitcoin U.S. ETF Index Options Contract Specifications (contract specs and operational details):
https://cdn.cboe.com/resources/membership/Cboe_Bitcoin_US_ETF_Index_Options_Contract_Specifications.pdf
