BlackRock Bitcoin ETF Filing: What PBIT Is and What It Would Do

The short answer: BlackRock has filed for a second bitcoin ETF, and this one is built to limit losses rather than track bitcoin outright. On October 19, 2026, iShares Trust filed Form 485APOS for the iShares Bitcoin Managed Protection ETF, ticker PBIT (SEC filing). PBIT is not approved and not trading. The filing leaves the management fee, total annual expenses and listing exchange blank, so the most important numbers for any decision do not exist yet. Data as of October 20, 2026.

What the filing actually says

The structure, per the filing:

• PBIT would hold three overlapping tranches of FLEX call option spreads on IBIT, BlackRock's existing spot bitcoin ETF.
• Each tranche buys calls at about 90% of IBIT's value, giving an initial floor of about 10% per tranche before fees.
• Each tranche sells higher-strike calls, which caps the upside.
• Alongside the options, the fund would hold cash and short-term fixed income.
• The fund may adjust the floor. The 10% figure is the initial setting, not a permanent promise.

The filing checks the box to become effective 75 days after filing. That points to roughly early January 2027, but it is an approximate date, not a launch announcement. The SEC can comment, and BlackRock can amend.

How a bitcoin protection ETF works, with a worked example

Take $10,000 and a clearly labelled hypothetical: assume a 20% cap and a 10% floor over one outcome period, before fees.

• If IBIT rallies well past the cap, you get about 20%. The sold calls give the rest of the move away.
• If IBIT falls hard, the floor limits the loss to about 10% before fees, so your position keeps roughly nine tenths of its value instead of tracking the full drop.
• If IBIT moves only a little either way, you get roughly that move, minus fees.

Two catches matter. First, the floor applies per tranche over its own period, not to your purchase date. If you buy mid-period after IBIT has already moved, your effective floor and cap are different from the starting figures. Second, fees come out of the protection. The filing says the floor is about 10% before fees, and the fee is one of the blanks.

What you give up versus plain IBIT

IBIT holds bitcoin with Coinbase Custody, tracks the CF Benchmarks index and trades on NASDAQ. As of October 20, 2026, IBIT sits at $46.65 with $67.1B in assets and a 0.25% expense ratio, down 8.11% year to date and down 25.62% over one year (21Rates IBIT profile). A 0.25% expense ratio on $10,000 costs $25 a year.

Choosing PBIT over IBIT means:

• You give up uncapped upside. IBIT holders keep all of a big rally. PBIT holders stop at the cap.
• You accept a defined floor instead of full downside. IBIT fell 25.62% over the past year; a protected structure is designed to absorb part of a move like that, before fees.
• You take on structure risk. FLEX options, overlapping tranches and an adjustable floor are more moving parts than a spot trust.
• You wait. IBIT trades today. PBIT is a filing.

PBIT against what already exists

Calamos runs protected bitcoin ETFs at three protection levels: 100% (CBOJ), 90% (CBXJ) and 80% (CBTJ), plus laddered versions (CBOL, CBXL, CBTL) launched October 14, 2025 at a 0.79% expense ratio (Calamos). CBXJ had 101 days left in its outcome period as of October 20, 2026. BITA, BlackRock's other newer fund, sells covered calls for monthly income and has no downside protection (21Rates on BITA).

The structural difference worth noting: Calamos funds run defined outcome periods with a stated cap and protection level that drift daily, while PBIT's filing describes three overlapping tranches with a floor the fund may adjust. Neither is the same product as spot exposure.

What is still unknown

• The management fee and total annual expenses. This decides how much of the floor fees eat.
• The listing exchange.
• The exact cap levels the tranches will set at launch.
• Whether and how the floor gets adjusted over time.
• The effective date. The 75-day box points to around early January 2027, but that is arithmetic, not a confirmed launch.

Frequently asked questions

Is PBIT approved and trading?

No. BlackRock filed Form 485APOS on October 19, 2026, and the filing checks the box to become effective 75 days later. That is an approximate timeline, not a confirmed launch date, and the SEC process can change it.

What is the PBIT expense ratio?

Unknown. The filing leaves the management fee, total annual expenses and listing exchange blank. The fee matters more than usual here because the stated floor is before fees, so costs directly reduce the protection.

Does PBIT protect me from bitcoin losses?

Only in a defined way. The filing describes an initial floor of about 10% per tranche before fees, built from FLEX call option spreads on IBIT, and the fund may adjust that floor. Protection applies per tranche over its own period, so buying mid-period changes your effective numbers.

How is PBIT different from IBIT?

IBIT holds spot bitcoin with Coinbase Custody and gives full upside and full downside at a 0.25% expense ratio. PBIT would cap upside and limit losses to a floor through options on IBIT. One is price exposure; the other is a shaped payoff.

Are there protected bitcoin ETFs trading already?

Yes. Calamos runs series at 100%, 90% and 80% protection levels, plus laddered versions, referencing the CBOE Bitcoin US ETF Index. CBXJ, the 90% fund, carries a 0.69% expense ratio and had $16.4M in net assets as of October 19, 2026.

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