How spot Bitcoin ETFs work: custody, creations, in-kind redemptions and why the price tracks

Who this is for: Allocators, advisers, treasurers and serious retail investors who want to understand what a spot Bitcoin ETF holds, how the creation and redemption machinery keeps it priced correctly, and how to compare the funds against each other and against holding bitcoin directly.

A spot Bitcoin exchange-traded fund is the product that turned bitcoin from something an institution had to figure out how to hold into something it could buy with the same ticket it uses for an S&P 500 fund. The structure is old and well understood. What was new in January 2024 was that US regulators allowed it to be pointed at bitcoin held directly, rather than at futures contracts, and the money that followed reshaped the market. By October 5, 2026 the US spot funds held roughly 1.29 million BTC, about 6.2 percent of everything that will ever exist, according to the Bitbo ETF tracker.

The plumbing matters because it explains almost everything an investor cares about: why the share price tracks bitcoin so closely, why the fee is deducted in bitcoin rather than cash, why the funds were less tax efficient in their first 18 months than they are now, and why the same template could be stamped onto Ether, Solana, XRP and a growing list of other assets within two years. This guide walks through the trust, the custodian, the authorized participants, the arbitrage, the 2025 rule changes on in-kind transfers and generic listing, the options market that grew on top of the largest fund, and the questions an allocator should ask before choosing one wrapper over another.

Spot Bitcoin ETFs by the numbers

What the fund actually holds

A spot ETF is a trust that owns bitcoin outright. The coins sit with a regulated custodian, overwhelmingly Coinbase Custody Trust Company for the US products (Grayscale’s GBTC names it directly in its fund documents), with a smaller number using Fidelity Digital Assets, Gemini or BitGo. The trust issues shares, each representing a fractional claim on the pool, and those shares trade on Nasdaq, NYSE Arca or Cboe BZX like any stock. IBIT, for example, lists on Nasdaq and had 1,422,160,000 shares outstanding on October 5, 2026, each backed by about 0.000566 BTC. The sponsor charges a management fee, between 0.14 and 0.25 percent a year for most of the large issuers as of October 2026, which is deducted from the trust’s holdings so the bitcoin per share declines very slowly over time.

Two technicalities are worth knowing. First, these products are not registered investment companies under the Investment Company Act of 1940. They are grantor trusts registered under the Securities Act of 1933 and listed under exchange rules for Commodity-Based Trust Shares, the same category as the physical gold ETFs. That is why their prospectuses carry the warning that the fund is “not an investment company” and why they are not subject to the 1940 Act’s diversification and governance rules. Second, the trust holds one asset and nothing else: no cash reserve beyond what is needed for fee payments and pending transactions, no lending of the bitcoin, and in the Bitcoin products no staking, because bitcoin cannot be staked.

How this differs from the earlier wrappers

The spot ETF is distinct from the futures-based ETFs approved in October 2021, which held CME bitcoin futures rather than coins and suffered from the cost of rolling contracts each month. It is also distinct from the Grayscale Bitcoin Trust in its original form, which for years traded at large premiums and discounts to its holdings because it had no redemption mechanism. Grayscale’s victory in the DC Circuit in August 2023, in which the court held that the SEC had failed to explain why it treated spot and futures products differently and vacated the disapproval order, was the legal turning point that made the January 2024 approvals all but inevitable. The SEC Chair’s January 10, 2024 statement cited that ruling as the reason the Commission changed course.

The participants and who gets paid

Five parties sit around the table. The sponsor (BlackRock’s iShares, Fidelity, Grayscale, Bitwise, ARK and 21Shares, Morgan Stanley and others) designs the trust, files the registration, markets the fund and collects the sponsor fee. The trustee, usually a Delaware trust company, holds legal title on behalf of shareholders. The custodian holds the private keys in segregated cold storage and is paid by the sponsor out of the fee. The authorized participants (APs) are large broker-dealers such as Jane Street, JP Morgan, Virtu and Macquarie that have signed agreements allowing them to create and redeem shares; they earn the arbitrage spread, not a fee from the fund. Finally, market makers, who may or may not also be APs, quote two-sided prices on the exchange all day and keep the bid-ask spread tight.

The money flow is simple. Investors buy shares on exchange and pay a commission or spread to their broker. The trust earns nothing; it only pays. Each day the sponsor fee accrues and the trust sells or transfers a sliver of bitcoin to cover it, which is why holdings per share drift down. For IBIT at 0.25 percent, a holder of 1,000 shares backed by 0.566 BTC on October 5, 2026 would see that backing fall to about 0.5646 BTC a year later with no price change at all. For a fund charging 0.14 percent the same position would fall to about 0.5652 BTC. The difference sounds trivial, and in a single year it is; over a decade it compounds into a meaningful gap, which the worked example below quantifies.

How creations and redemptions keep the price honest

The feature that makes an ETF an ETF is the creation and redemption process. An AP can deliver assets to the trust and receive new shares in a basket, or hand a basket of shares back and take assets out. For IBIT the basket is 40,000 shares, and the trust publishes each morning how much bitcoin a basket is worth: 22.64 BTC on October 5, 2026. If the ETF trades above the value of its bitcoin, an AP creates shares and sells them, pushing the price down. If it trades below, an AP buys shares and redeems them. That arbitrage is why spot ETFs track their net asset value within a few basis points, where the old Grayscale trust could drift 40 percent away. IBIT’s published premium on October 2, 2026 was 0.19 percent, and most days it sits closer to zero.

1. Price discovery. Shares trade on exchange during US market hours. Bitcoin trades 24 hours a day, so the ETF’s market price reflects the live bitcoin price while the official NAV is struck once a day, at 4 pm New York time for most funds, using a reference rate such as the CME CF Bitcoin Reference Rate New York Variant.
2. Premium or discount appears. Heavy buying pushes the shares above the value of the underlying; heavy selling pushes them below.
3. AP acts. At a premium, the AP sells shares short on exchange, buys bitcoin (or, under the cash model, delivers dollars), and submits a creation order before the daily cut-off. At a discount, the AP buys shares cheaply, submits a redemption, and receives bitcoin or cash worth more than it paid.
4. Settlement. Shares settle through DTC on T+1. Bitcoin moves between the AP’s (or its agent’s) custody account and the trust’s custody account, typically within the same custodian.
5. Gap closes. The AP’s trading pressure moves the share price back toward NAV. The AP keeps the difference, minus transaction costs and the creation fee the trust charges per basket.

Cash model versus in-kind model

At launch in January 2024 the SEC insisted on cash creations: the AP delivers dollars, the trust (through its sponsor and a trading counterparty) buys bitcoin, and the reverse on redemption. That kept broker-dealers from touching bitcoin directly but added trading costs, introduced timing risk between the cash order and the bitcoin purchase, and made the funds less tax efficient because redemptions could force the trust to sell coins. On July 29, 2025 the Commission approved exchange proposals to permit in-kind creations and redemptions for bitcoin and ether ETPs, the standard model for commodity and equity ETFs, so APs can now deliver and receive bitcoin itself. The SEC’s release said the change would reduce costs and improve market efficiency for issuers, APs and investors. The same day the Commission approved FLEX options on bitcoin ETPs and raised position limits on listed options for certain bitcoin ETPs to 250,000 contracts. Most of the major issuers filed to adopt in-kind within weeks, and by late 2025 in-kind was the default for the large funds, with cash retained as an alternative.

Why it matters to a holder: under in-kind redemption, the trust hands over bitcoin rather than selling it, so no taxable gain is realised inside the trust. Under the cash model, a wave of redemptions in a rising market could have left remaining holders with the trust’s realised gains, as can happen in mutual funds. In practice the grantor trust structure already passed through tax consequences to each holder based on their own cost basis, so the benefit is mostly about execution cost and tracking precision rather than a wholesale change in tax treatment. The tax position of the individual investor is covered in the CCS guide to US crypto tax rules.

The scale of what happened

Eleven spot Bitcoin ETFs began trading on January 11, 2024. BlackRock’s iShares Bitcoin Trust (IBIT) became the fastest ETF ever to reach $10 billion, then $50 billion, and by 2025 had passed the assets of the firm’s own gold fund. On October 5, 2026 IBIT reported net assets of $68.99 billion, 1.42 billion shares outstanding and a 30-day average volume of about 45 million shares a day, according to the iShares fund page. Farside Investors’ flow tally put IBIT’s cumulative net inflows since launch at about $65.8 billion, against roughly $27.9 billion of cumulative outflows from GBTC, which started 2024 with the most assets but the highest fee.

Across all US funds, cumulative net inflows reached about $57.8 billion by September 30, 2026 and roughly $58 billion after the first three trading days of October, per Farside. The combined funds held 1,293,818 BTC worth $111.5 billion on October 5, 2026, per Bitbo, which sources holdings from the issuers’ own pages. That is about 6.16 percent of the maximum supply, a larger stake than any single company or government is known to hold, and it made daily ETF flow data a market signal in its own right. The late September 2026 run of inflows, including a $999 million day on September 21 and $715 million on September 22, was followed by net outflows of $149 million on September 30 and $90 million on October 5, a reminder that the direction of flows can flip quickly.

Sources: Bitbo US ETF holdings (October 5, 2026) and Farside Investors cumulative flow table (October 5, 2026). Hashdex’s DEFI, the thirteenth fund, reported no bitcoin holdings on that date. Figures are rounded.

The demand came from a mix of registered investment advisers allocating on behalf of clients, hedge funds running basis trades between the ETF and CME futures (explained in the CCS basis trade guide), corporate and treasury-style holders who prefer a listed security to a custody relationship, and a growing list of institutions whose mandates permit exchange-listed securities but not direct crypto holdings. That last group is the reason the ETF mattered structurally: it moved bitcoin inside the perimeter of existing compliance, custody and reporting systems rather than asking those systems to change. Morgan Stanley’s own entry with MSBT, priced at 0.14 percent and holding more than 10,500 BTC by October 5, 2026, shows how far the wirehouses moved from merely permitting the trade to sponsoring the product.

Options, leverage and the derivatives layer

Listed options on IBIT began trading on Nasdaq in November 2024 after the SEC, CFTC and OCC each cleared the product, and options on several other spot funds followed. The market grew quickly because it gave institutions a regulated way to buy protection, sell covered calls for income, or express directional views with defined risk, all inside a brokerage account. The SEC’s July 29, 2025 actions widened the channel further: FLEX options with customised strikes and expiries were approved on bitcoin ETPs, and position limits for certain bitcoin ETP options were raised to 250,000 contracts, which matters for large hedgers who had been constrained by the earlier 25,000-contract ceiling. In September 2025 the Commission also approved p.m.-settled bitcoin index options on Cboe exchanges.

The derivatives layer feeds back into the spot product. Market makers hedging options positions buy and sell the ETF shares themselves, which deepens liquidity and tightens spreads in the largest fund more than in smaller rivals, and dealers hedging in futures link the ETF’s price to the CME basis, which is why ETF flows, CME open interest and the funding rates covered in the CCS perpetuals guide are read together by professional desks. The practical consequence is that liquidity is concentrated: IBIT carries most of the options open interest and most of the daily share volume, so a smaller fund with a lower fee may cost more to trade in size than the fee saving is worth.

Beyond Bitcoin: the ETF wave of 2024 to 2026

Spot Ether ETFs were approved in May 2024 and began trading in July 2024. They gathered assets more slowly at first because the funds could not stake the ether they held, which meant holders gave up the network’s native yield. That changed in 2025 and 2026: the SEC’s August 2025 staff statement on liquid staking and subsequent exchange filings opened the way for staking inside the wrapper, and BlackRock now runs both an unstaked iShares Ethereum Trust (ETHA, $9.94 billion in net assets on October 5, 2026) and a separate iShares Staked Ethereum Trust (ETHB). Cumulative net inflows into US spot Ether ETFs stood at about $13.8 billion on October 5, 2026 per Farside, with ETHA at $13.2 billion against outflows of $5.4 billion from Grayscale’s legacy ETHE, which charges 2.50 percent. The mechanics of staking, and what it changes about the risk of the fund, are covered in the CCS staking guide.

The SEC’s approval of generic listing standards for Commodity-Based Trust Shares on September 17, 2025 was the second structural change of that year. Under the standards, Nasdaq, NYSE Arca and Cboe BZX may list a qualifying crypto ETP without first filing a proposed rule change under Section 19(b) of the Exchange Act, which had meant a review of up to 240 days per product. The Commission approved the Grayscale Digital Large Cap Fund, a multi-asset product tracking the CoinDesk 5 index, the same day. Within six weeks the first products listed under the new regime: the Bitwise Solana Staking ETF (BSOL) began trading on NYSE on October 28, 2025 at a 0.20 percent fee with a significant portion of its SOL staked through Helius, and the Bitwise XRP ETF (ticker XRP) followed on NYSE on November 20, 2025 at 0.34 percent, after rival XRP products earlier that month. By October 2026 Farside was tracking seven US spot Solana funds, including Fidelity, VanEck, 21Shares, Franklin, Grayscale and a Morgan Stanley product at 0.14 percent, with about $1.6 billion of cumulative net inflows.

The wave kept going in 2026. Bitwise launched a spot Avalanche ETP (BAVA) on April 15, 2026 and a spot Hyperliquid ETF (BHYP) on May 14, 2026; by October 5, 2026 three Hyperliquid funds (Bitwise, 21Shares and Grayscale) had drawn about $349 million. A 21Shares Zcash product (ZCSH) was trading at a 2.50 percent fee with around $225 million of inflows, and the Bitwise NEAR ETF (NRR) launched on September 29, 2026 as the first US spot NEAR product. The CCS ETF tracker counted 46 crypto ETFs across eight assets and 16 issuers as of its last update. The same creation and redemption mechanics apply to all of them; what differs is the liquidity and custody depth of the underlying asset, which is thinner outside the top two and worth examining before assuming a new product will track as tightly as IBIT does. See the CCS Solana guide for the network behind the second-largest altcoin ETF category.

What an allocator should look at

The products are close substitutes, so the decision usually comes down to a short list of factors. Fee is the obvious one, and the range widened in 2026 when Morgan Stanley’s MSBT and Grayscale’s Mini Trust undercut the 0.25 percent set by IBIT and FBTC, but at the level of a few basis points it matters less than liquidity: the largest funds have the tightest bid-ask spreads and the deepest options markets, which is where much of the institutional activity now happens. An investor paying a 5 basis point spread to get in and out of a thin fund has given back several years of a 10 basis point fee advantage.

Custodian concentration is a real consideration, since a single custodian holds the majority of ETF bitcoin. The SEC’s October 1, 2026 proposal on crypto custody for advisers and funds, which would allow state trust companies to act as qualified custodians and set conditions for self-custody, could broaden the field over time, but as of October 2026 the concentration remains. The CCS custody guide explains how segregated cold storage, key ceremonies and insurance differ across providers. Tax treatment depends on the wrapper and the holder’s jurisdiction; US holders of grantor trusts receive a share of the trust’s gains and expenses on their own return, and the in-kind change improved execution for the funds themselves. Finally, an ETF gives price exposure and nothing else: no ability to move coins on-chain, no lending yield in the Bitcoin products, and no self-custody. For many institutions that is precisely the point; for a holder who values the ability to transact or to hold keys, the comparison in the CCS self-custody guide is the right starting place.

How we got here: a timeline

Worked example: the arbitrage, and the fee drag over a decade

How to evaluate a spot crypto ETF: a checklist

• What is the all-in cost, not just the sponsor fee? Add the typical bid-ask spread and any brokerage commission to the headline fee. A 0.14 percent fund with a 6 basis point spread can cost more over a short hold than a 0.25 percent fund trading at 1 basis point.
• How tightly has it tracked NAV? Issuers publish daily premium and discount history. IBIT showed a 0.19 percent premium on October 2, 2026; a fund that regularly swings beyond 0.5 percent has thin AP coverage.
• Who is the custodian and how is the bitcoin held? Look for segregated cold storage, named insurance limits and a published custody agreement. Note whether the fund shares a custodian with most of its peers.
• Does it use in-kind creations and redemptions? Since July 29, 2025 the large funds can. In-kind lowers execution cost and avoids forced sales inside the trust.
• Is there a liquid options market? Options exist on IBIT and several peers. If you intend to hedge or write calls, the fund with the deepest options book is usually worth a few basis points of fee.
• How large and how old is the fund? Funds under a few hundred million dollars face closure risk and wider spreads. Check that the sponsor has committed capital rather than relying on fee waivers that expire.
• For non-Bitcoin funds, does it stake, and who runs the validators? BSOL stakes through Helius and states that a significant portion of SOL is staked. Unstaked Ether and Solana funds give up the network yield entirely.
• What are the tax mechanics in your jurisdiction? US grantor trusts pass through expenses and gains; other wrappers differ. Confirm before assuming the ETF is treated like a stock.
• Does the underlying market support the size? Bitcoin and Ether have deep spot and CME futures markets. For Hyperliquid, NEAR or Zcash, thinner liquidity makes AP arbitrage more expensive and tracking looser.

Risks and open questions

The first risk is concentration. One sponsor holds roughly 62 percent of all ETF bitcoin (IBIT’s 805,222 BTC against a 1.29 million total on October 5, 2026), and one custodian holds the majority of the coins for most sponsors. An operational failure, a key compromise or a regulatory action against that custodian would affect many funds at once. The structure includes insurance, segregated accounts and bankruptcy-remote trusts, but it has not yet been tested by a custodian failure.

The second is market structure. ETF flows now move the bitcoin price, and the funds trade only during US equity hours while bitcoin trades continuously. Large overnight moves create gaps at the open that APs must arbitrage in a hurry; in stressed conditions, as in the sharp outflow days of 2025 and the September 30, 2026 reversal, spreads widen and the premium or discount can persist for hours. Options hedging adds reflexivity: dealers short gamma sell into declines and buy into rallies, which can amplify moves in the ETF and, through the APs, in bitcoin itself.

The third is regulatory. The 2024 approvals rested on a court decision and the 2025 changes on a Commission that has made digital assets a priority. A future Commission could tighten listing standards, impose custody conditions through the October 2026 proposal, or revisit staking inside ETPs. The CCS guide to SEC and CFTC jurisdiction covers where the lines currently sit. For the altcoin funds there is an additional question about whether the underlying asset is a security; the generic standards did not settle that, they only set conditions under which an exchange may list.

What to watch next

Glossary

Authorized participant (AP)

A broker-dealer with an agreement to create and redeem ETF shares in baskets directly with the trust. APs are the only parties who can expand or shrink the share count.

Basket

The fixed block of shares, 40,000 for IBIT, that an AP creates or redeems at once, and the amount of bitcoin that block represents on a given day.

Cash creation

A creation in which the AP delivers dollars and the trust buys the bitcoin. Required for US spot crypto ETPs from January 2024 until the SEC permitted in-kind transfers in July 2025.

Commodity-Based Trust Shares

The exchange listing category used for physical gold ETFs and spot crypto ETPs. Generic listing standards for this category were approved on September 17, 2025.

Custodian

The regulated entity that holds the trust’s private keys, typically in segregated cold storage. Coinbase Custody serves most US spot funds.

FLEX options

Exchange-listed options with customisable strike, expiry and exercise style, approved on bitcoin ETPs in July 2025.

Grantor trust

The legal form of US spot crypto ETPs. Holders are treated as owning their share of the underlying asset directly for tax purposes.

In-kind creation or redemption

A transfer in which the AP delivers or receives the underlying bitcoin itself rather than cash. Standard for commodity ETFs and permitted for crypto ETPs since July 29, 2025.

Net asset value (NAV)

The value of the trust’s bitcoin, minus accrued fees, divided by shares outstanding, struck once daily from a reference rate.

Premium or discount

The gap between the exchange price of a share and its NAV. Arbitrage by APs keeps it small; closed-end trusts without redemptions can see gaps of 40 percent.

Reference rate

A benchmark price, such as the CME CF Bitcoin Reference Rate New York Variant, computed from several exchanges and used to strike NAV.

Sponsor fee

The annual charge, 0.14 to 1.50 percent across US spot Bitcoin ETFs in October 2026, deducted from the trust’s bitcoin to pay the sponsor, custodian and other service providers.

Staked ETP

A fund that delegates some of its proof-of-stake holdings to validators and passes rewards to shareholders, such as BSOL or the iShares Staked Ethereum Trust (ETHB).

19b-4 filing

An exchange’s proposed rule change submitted to the SEC under Section 19(b) of the Exchange Act, the route every spot Bitcoin and Ether ETF took before generic listing standards existed.

Why it matters

The spot Bitcoin ETF did not change what bitcoin is. It changed who could own it and how. In under three years a product that regulators had rejected for a decade became the holder of more than 6 percent of the supply, drew roughly $58 billion of net new money, spawned a derivatives market and a dozen imitators on other assets, and forced the SEC to rewrite the listing and transfer rules for the whole category. The creation and redemption mechanism at the centre of it is unglamorous, but it is the reason a pension fund can treat bitcoin exposure as just another line item, and the reason the share price it sees is the price of the asset and not the price of a story.

The lesson is that structure beats narrative. Grayscale’s trust held the same bitcoin for years and traded at the wrong price because it lacked redemptions. The same coins inside an ETF trade at the right price because a handful of arbitrageurs are paid a few basis points to make it so. Everything that followed, from in-kind transfers to generic listing to staked funds, is an extension of that one idea.

Sources

1. SEC: Statement on the Approval of Spot Bitcoin Exchange-Traded Products, January 10, 2024
2. SEC: SEC Permits In-Kind Creations and Redemptions for Crypto ETPs, July 29, 2025
3. SEC: Division of Corporation Finance Issues Staff Statement on Certain Liquid Staking Activities, August 5, 2025
4. SEC: SEC Approves Generic Listing Standards for Commodity-Based Trust Shares, September 17, 2025
5. SEC: SEC Proposal Would Address How Investment Advisers and Funds Can Custody Crypto Assets, October 1, 2026
6. iShares: iShares Bitcoin Trust ETF (IBIT) fund page, net assets, basket and shares outstanding, October 5, 2026
7. iShares: iShares Ethereum Trust ETF (ETHA) fund page, October 5, 2026
8. Grayscale: Grayscale Bitcoin Trust ETF (GBTC) fund page, sponsor fee and custodian, accessed October 6, 2026
9. Bitwise: The Bitwise Solana Staking ETF (BSOL) Begins Trading, October 28, 2025
10. Bitwise: Bitwise XRP ETF (Ticker: XRP) Begins Trading on NYSE, November 20, 2025
11. Bitwise: Bitwise Launches Spot Avalanche ETP (BAVA), April 15, 2026
12. Bitwise: Bitwise Launches Spot Hyperliquid ETF (BHYP), May 14, 2026
13. Bitwise: The Bitwise NEAR ETF (NRR) Launches as First Spot NEAR ETP in the US, September 29, 2026
14. Farside Investors: Bitcoin ETF Flow, daily and cumulative, with fee table, October 5, 2026
15. Farside Investors: Ethereum ETF Flow, October 5, 2026
16. Farside Investors: Solana ETF Flow, October 5, 2026
17. Farside Investors: Hyperliquid ETF Flow, October 5, 2026
18. Farside Investors: Zcash ETF Flow, October 5, 2026
19. Bitbo: US Bitcoin ETF holdings by fund, October 5, 2026
20. Crypto Coin Show: Crypto ETF Tracker, accessed October 6, 2026

Disclosure: This guide is reviewed and updated as the rules and the market change. It is for education only and is not investment, legal or tax advice.