Your Ten-Asset Crypto Index Is Mostly Two Assets

That is not a criticism of either product. It is what market-cap weighting does in a market shaped like this one. But if you bought an index fund because you wanted to stop being so exposed to bitcoin, you should know that the fund did not really solve that for you.

Why counting holdings tells you nothing

Here is the thing people get wrong about diversification. They count names.

A portfolio’s actual diversification depends on weights, not on how many tickers appear in the holdings table. Ten assets where two carry 90% of the weight is, in behaviour, a two-asset portfolio. The other eight move the needle by fractions of a percent on a normal day.

You can test this yourself without any tools. Take the fund’s daily return and plot it against bitcoin’s daily return over a year. If the dots fall close to a straight line, the eight small holdings are decoration.

The reason is arithmetic. If an asset holds 1.5% of the index and it doubles in a day, it adds 1.5% to the index. Meanwhile bitcoin moving 3% in the other direction takes away more than that. The small positions are real, but they are not large enough to change the story.

Why this happens

Crypto index funds are concentrated because the crypto market is concentrated, and market-cap weighting reproduces whatever it is pointed at.

Bitcoin dominance has sat around 57% through much of 2026, and once you strip stablecoins out of the denominator the figure is higher still. Ether takes a large slice of what remains. Everything else in the market splits a much thinner layer.

An index that weights by market cap is not making a judgement here. It is holding a mirror up to a market where two assets genuinely are most of the value. The mirror is accurate. It is just that “accurate” and “diversified” are different goals, and most index marketing quietly implies you are getting both.

There is a second reason worth knowing about, specific to the Bitwise index. Since August 2025 its methodology requires at least 87.5% of the index weight to sit in assets that already have an SEC-approved single-asset ETP. That rule pushes weight toward the largest, most established names, which reinforces the concentration rather than offsetting it.

What actually changes the weights

Three approaches exist, and the difference between them is much larger than the difference between “five assets” and “ten assets.”

Pure market-cap weighting. What BITW and GDLC do. Faithful to the market, maximally concentrated. Simple to explain, simple to implement, and it will always look like bitcoin.

Capped market-cap weighting. What the CoinDesk 20 does. The largest constituent is capped at 30%, every other at 20%, and the excess is redistributed. The stated target is roughly half the index in bitcoin and ether combined, half across the other eighteen assets. That is a genuine structural difference, not a cosmetic one.

Equal weighting. Every constituent gets the same slice regardless of size. Maximum breadth, and the highest turnover, because every rebalance means trimming winners and topping up losers.

The gap between bar one and bar three in that diagram is the entire question. Everything else — the constituent count, the rebalance schedule, the fee — matters less than which of those three shapes you actually bought.

When concentration helps and when it hurts

Concentration is a directional bet, not a flaw. It pays off and it costs you, in alternating regimes.

When bitcoin leads, a heavily concentrated index outperforms a capped or equal-weighted one, straightforwardly, because it holds more of the thing that is going up. The 2024 to 2026 stretch has largely looked like this. Spot bitcoin ETFs pulled institutional money directly into BTC rather than spreading it across the market, and no single altcoin narrative emerged with the pull of the 2017 ICO wave or the 2021 DeFi and NFT cycle.

When the market broadens, the same index lags. A capped index that forces half its weight into eighteen other names captures a rotation that a market-cap index mostly misses. The altcoin season index is the cleanest way to see which regime you are in: it counts how many large-cap altcoins beat bitcoin over the trailing 90 days.

So the honest framing is not “concentrated is bad.” It is that a market-cap crypto index is a bet on continued bitcoin leadership, whether or not anyone described it to you that way.

What to do about it

If concentration is what you want, market-cap index products give it to you cheaply and with one ticker. Nothing further needed.

If it is not what you want, there are three routes and each has a cost.

Buy a capped index instead. Capped constructions like the CoinDesk 20 do the redistribution for you. The cost is that you will underperform in bitcoin-led markets, which has been most of the recent past.

Hold the index fund and a separate alt sleeve. Pair a concentrated product with an ex-bitcoin basket to dial the exposure yourself. The cost is two positions to manage and rebalance. CI-Alts is the display version of that sleeve.

Build the basket manually. Buy the assets and set your own weights. The cost is custody, execution, tax reporting, and the discipline to actually rebalance rather than letting winners run, which is the exact behaviour an index exists to prevent.

Before choosing, do one thing: open the fund’s current holdings page and add up the weight of bitcoin and ether. Not the constituent count. The weight. That single number tells you more about how the product will behave than the entire fact sheet around it.

Most people who do this for the first time are surprised. That reaction is the useful part.

Verify current holdings and weights on the issuer’s page before acting on any of this. Cryptoindex.ai publishes index data and analysis for informational purposes and is not affiliated with any fund issuer named here. Nothing on this page is investment advice.