The case for a crypto index fund is the same as the case for any index fund: you do not have to pick, you do not have to rebalance, and you get the category rather than a bet inside it. The complication specific to this asset class is that the category is overwhelmingly one asset, which makes the fee arithmetic harder to justify than it first appears.
What a crypto index fund is
A fund holding several cryptoassets in proportions set by a published, rules-based methodology rather than by a manager's judgement. The index provider decides what is eligible, how much of each to hold, and when to rebalance. The fund follows.
Note that "index" and "ETF" describe different things and get conflated constantly. An index fund is defined by what it tracks; an ETF is defined by how it trades. A single-asset spot bitcoin fund is exchange traded but not an index fund in any meaningful sense — there is nothing to index. BITW and GDLC are both.
The two main products
| Ticker | Fund | Fee | Detail |
|---|---|---|---|
| BITW | Bitwise 10 Crypto Index ETF | 0.75% | Tracks the ten largest cryptoassets by free-float market capitalisation. Converted to an ETP on 3 December 2025 and began trading on NYSE Arca on 9 December 2025. Eleven holdings in the portfolio, with the top ten making up roughly 97.1% of assets. |
| GDLC | Grayscale CoinDesk Crypto 5 ETF | 0.59% | Converted from the Grayscale Digital Large Cap Fund and began trading with about $865m in assets. Tracks a five-asset CoinDesk index. |
Conversion dates, fees, holdings and assets from SEC filings — Form 10-K (FY2025) for BITW and Form FWP for GDLC — and issuer disclosures.
Both arrived by converting an existing closed-end trust rather than launching cold, which is the same route GBTC and ETHE took. The conversion is what gave them the creation and redemption mechanism that keeps the share price tracking the underlying basket — before it, these vehicles could and did trade at persistent premiums and discounts to the value of what they held.
What is actually inside
GDLC published its holdings at a September 2025 snapshot, and the shape of it is the single most useful fact on this page.
| Asset | Weight | Notes |
|---|---|---|
| Bitcoin | 72.09% | Dominates the basket by a very wide margin |
| Ether | 17.08% | Second by some distance |
| XRP | 5.67% | |
| Solana | 4.12% | |
| Cardano | 1.04% | Roughly one pound in every hundred |
Holdings as disclosed in Grayscale SEC filings at 18 September 2025. Index weights change at every rebalance and with market movements — this is a point-in-time snapshot, not the current position. BITW weights are set by the same broad principle (free-float market capitalisation) and will be similarly concentrated.
The concentration problem
Look at that table again. Bitcoin is 72% of a fund marketed on the strength of holding five different assets. Bitcoin and ether together are just over 89%. The remaining three assets share about a tenth of the fund between them, with cardano at roughly one pound in every hundred.
This is not a criticism of the index construction — it is what market-capitalisation weighting does, and it does the same thing in equity indices, where a handful of large technology companies dominate. It is a criticism of how these products are understood by the people buying them.
If you buy GDLC expecting meaningful diversification away from bitcoin, you have bought something that is roughly three-quarters bitcoin. A cardano allocation of 1.04% would need to multiply many times over to move your total position by a single percentage point.
The test we would apply
Strip the basket down to what it actually adds over just holding bitcoin: in GDLC's case, about 28% spread across four other assets, of which ether is most of it. Then ask whether you would deliberately buy that 28% allocation as a standalone position. If yes, the fund is a reasonable way to get it. If no, you are paying 0.59% for exposure that is largely bitcoin, when a bitcoin fund is available at 0.15%.
Is the fee worth it?
The honest answer is that it depends on what you would otherwise do, and the arithmetic is worth running rather than assuming.
Against holding bitcoin alone. You pay roughly 0.44 percentage points more annually (0.59% against 0.15%) for a basket that is 72% bitcoin. In effect, the extra 28% of the fund is costing you far more than 0.44% on its own terms, because you are paying the higher fee on the bitcoin portion as well.
Against building the basket yourself. This is where the index product justifies its fee. Buying five cryptoassets in specified proportions, rebalancing them periodically, and computing the tax on every rebalance is genuinely laborious — and under HMRC's rules every rebalancing swap between coins is a chargeable disposal. One ticker producing one tax line is worth real money to anyone holding directly and outside a wrapper.
Against doing nothing. If the alternative is not investing in this category at all, the fee is not the relevant variable and the volatility of the underlying is.
Reading the methodology
The index methodology is the document that actually determines what you own, and almost nobody reads it. Four things in it are worth finding.
Eligibility criteria. BITW's index considers trading activity, whether the asset can be held with regulated custody providers, security characteristics and regulatory considerations. That last one matters: an asset facing a regulatory challenge can be excluded, and that decision is made by the index provider rather than by you.
Weighting scheme. Free-float market capitalisation in both cases, which is what produces the concentration described above. Some indices cap the largest holding; these do not, in any way that changes the picture.
Rebalancing frequency. Determines how promptly the fund reacts when an asset's market capitalisation moves, and how many taxable events happen inside the fund.
Addition and removal rules. What happens when a new asset qualifies or an existing one falls out. In a market where a coin can lose most of its value in weeks, this is not academic.
The UK position
Neither BITW nor GDLC is available to a UK retail investor. They are US-listed funds and the FCA restriction applies.
The London market has not produced a close equivalent. Issuers listing in the UK after October 2025 concentrated on single-asset bitcoin and ether notes, which is where they judged the demand to be. A UK investor wanting basket exposure through listed products would have to build it from two or more individual notes — which reintroduces the rebalancing and record-keeping the index product exists to remove, and does so without the tax efficiency of rebalancing inside a fund.
The practical alternatives are holding the assets directly and rebalancing yourself, or accepting single-asset exposure. The one genuinely ISA-eligible basket route in this sector is an equity ETF holding crypto-related company shares — a different exposure entirely, covered on blockchain and miner ETFs.
Our view
We think these products are better understood as a convenience purchase than as a diversification purchase, and priced accordingly.
What they genuinely deliver is operational: one holding, one line on a tax return, no rebalancing decisions, and someone else deciding when an asset should leave the basket. For an investor who wants the category and does not want to manage it, that is worth paying for.
What they do not deliver is meaningful diversification away from bitcoin, because market-cap weighting cannot. Anyone buying one of these on the assumption that it spreads risk across ten different assets has misread what the weights do. Cryptoassets in a basket remain high risk, the correlation between the constituents in a falling market has historically been high, and past performance is not a reliable indicator of future events.
Crypto index funds: questions
What is a crypto index ETF?
A fund that holds a rules-based basket of cryptoassets rather than a single coin, with weights set by a published methodology and rebalanced periodically. The two main US products are the Bitwise 10 Crypto Index ETF (BITW), which tracks the ten largest cryptoassets by free-float market capitalisation at a 0.75% fee, and the Grayscale CoinDesk Crypto 5 ETF (GDLC), which holds five assets at 0.59%.
The appeal is one ticker, one tax line and no rebalancing work on your part. The catch is that these baskets are far more concentrated than the word "index" suggests.
What is in the Bitwise 10 Crypto Index ETF?
The ten largest cryptoassets by free-float market capitalisation, with eligibility determined by reviewing trading activity, custody with regulated providers, security characteristics and regulatory considerations. Weights are assigned by free-float market value. The portfolio held eleven positions, with the top ten accounting for approximately 97.1% of assets. Because weighting is by market capitalisation, bitcoin dominates the basket.
Is a crypto index fund better than just buying bitcoin?
It depends entirely on what you think the extra 25–30% of the basket is going to do, because that is all you are buying. At a market-cap weighting, bitcoin is roughly 72% of a five-asset basket and a comparable share of a ten-asset one. You are paying 0.59% or 0.75% rather than 0.15% for exposure that is mostly bitcoin, in exchange for a minority allocation to ether and a small tail of other assets. If you would not deliberately allocate to that tail, the index wrapper is an expensive way to acquire it.
Can I buy BITW or GDLC in the UK?
No. Both are US-listed exchange traded products and the FCA restriction on crypto ETFs for UK retail consumers applies. The London market has concentrated on single-asset bitcoin and ether notes rather than multi-asset baskets, so a direct UK equivalent is not readily available. A UK investor wanting basket exposure would generally build it from individual notes, or hold the assets directly.
How often do these funds rebalance?
The rebalancing schedule and the rules governing it are set out in the index methodology rather than being a matter of the sponsor's discretion, and each index differs. This is one of the genuinely important documents to read before buying a basket product, because the methodology decides what enters, what leaves, and how promptly the fund reacts when an asset's market capitalisation moves. Both sponsors publish it.
Sources & further reading
- SEC EDGAR — Bitwise 10 Crypto Index ETF, Form 10-K (FY2025)
- SEC EDGAR — Grayscale CoinDesk Crypto 5 ETF, Form FWP
- ETFdb — Grayscale launches first multi-crypto ETP, GDLC
- Bitwise — BITW fund page
Figures on this page were checked against the sources above on the date shown at the top of the article. Fund sizes, fees and product availability change; always confirm current numbers on the issuer's own factsheet or KID before acting.