How Do Bitcoin ETFs Track the Bitcoin Price?

Spot Bitcoin ETFs launched in the United States in January 2024, and within a year they had taken in more assets than any ETF category before them. But they work differently from every other ETF in one important respect — and it is a difference that catches holders out every weekend.

This is the thing to understand before anything else. Bitcoin trades continuously, on exchanges that never close. IBIT, FBTC and GBTC trade on US exchanges between 9:30 and 16:00 ET, Monday to Friday — about 32 hours a week out of 168.

So on a Saturday, the share price you see in your brokerage app is Friday’s close. Bitcoin itself has been moving the entire time. If it dropped 8% overnight on Saturday, your IBIT position will not reflect that until Monday’s open, when it will gap.

This one fact causes most of the confusion people have with these products. It is also why the Bitcoin ETF Calculator only samples prices while the equity market is open — comparing a live Bitcoin price against a frozen share price produces a ratio that is simply wrong.

Given that the fund trades for a fifth of the hours that Bitcoin does, what stops the share price from drifting arbitrarily far from the value of the Bitcoin it holds?

The answer is the creation and redemption mechanism. Large institutions — authorised participants — can hand Bitcoin to the fund and receive newly created shares, or hand back shares and receive Bitcoin. The fund publishes a basket size daily, and the arbitrage works like this:

• If shares trade above the value of their Bitcoin, an AP creates shares and sells them, pushing the price down.
• If shares trade below, an AP buys shares, redeems them for Bitcoin, and sells the Bitcoin, pushing the price up.

That arbitrage is what keeps an ETF tracking its underlying asset. It is the difference between an ETF and a closed-end trust: GBTC spent years trading at a discount of up to 40% precisely because it had no creation mechanism before its 2024 conversion.

The mechanism does not make the gap zero. It makes it small and self-correcting.

Bitcoin ETF shares typically trade within a few tenths of a percent of their net asset value. The gap widens when markets are volatile, when the underlying is moving fast, or when the arbitrage is difficult to execute — which for Bitcoin means weekends and holidays, exactly when the fund is closed anyway.

This is why a calculator gives you a theoretical fair value rather than a quote. The conversion is mathematically correct, but the price you can actually transact at includes whatever premium or discount the market is applying at that moment.

Gold ETFs pay their management fee by selling a little gold each year. Bitcoin ETFs do the same thing with Bitcoin, which means the amount of Bitcoin backing each share declines over time.

IBIT charges 0.25%. FBTC charges 0.25%. GBTC charges 1.50% — six times as much — which is why it has seen steady outflows since the conversion. Over a decade, the difference between 0.25% and 1.5% is roughly 12% of your position, taken out of the Bitcoin itself.

The practical consequence for anyone using a calculator: the ratio between the ETF price and the Bitcoin price is not constant. It drifts down every day the fund operates. A fixed ounces-per-share or Bitcoin-per-share figure typed into a spreadsheet will be wrong within a year.

Holding IBIT is not the same as holding Bitcoin in your own wallet. You own shares in a trust; the trust owns Bitcoin; a custodian holds the private keys. You have no claim on specific coins and no keys of your own.

For most people this is the point — it removes the operational risk of self-custody entirely. It does replace it with counterparty risk, which is a different thing rather than no thing. Whether that trade is worth making depends on why you hold Bitcoin in the first place.

It is worth being concrete about what the 24/7 mismatch costs a holder, because the abstract version of the warning does not land.

Say you hold $50,000 of IBIT and Bitcoin falls 10% over a weekend. IBIT cannot move. Monday morning it does not open down 10% gradually — it opens where the underlying value now is, which is roughly $45,000. Your stop-loss order, if you had one resting at, say, $47,000, does not execute at $47,000. The market opens below it and you are filled somewhere near the open.

This is the practical reason the mismatch matters. It is not that the ETF is mispriced — it is not, once it opens. It is that there is no continuous market in between, so you cannot react and your resting orders cannot protect you.

It cuts the other way too. Someone wanting to buy Bitcoin exposure on Saturday night because prices dropped cannot do it through the ETF until Monday, by which time the opportunity may be gone.

IBIT and FBTC charge the same fee, so the choice between them is mostly about which brokerage you use and whether you want the option to trade options later — FBTC’s chain is thinner. Both are far larger and more liquid than anything below them.

GBTC is the historical oddity. It existed as a closed-end trust from 2013, and for years it was the only way to hold Bitcoin in a US brokerage account. That scarcity let it trade at a large premium — until 2021, when the premium collapsed and flipped into a discount that at one point exceeded 40%, trapping holders who had bought above net asset value.

The discount persisted because GBTC had no creation mechanism to arbitrage it away. When it converted to an ETF in January 2024, that mechanism arrived, the discount closed within days, and the 1.50% fee became the reason to leave rather than the reason to stay.

The Bitcoin ETF Calculator converts in both directions across IBIT, FBTC and GBTC. Enter a Bitcoin price to see what each share would be worth, or enter a share price to see what it implies about Bitcoin.

The ratios are recalculated from live prices for the reason described above — they are not constants, and treating them as constants is the mistake almost every static converter makes. Between the fee erosion and the premium/discount, a figure typed into a spreadsheet is stale faster than most people expect.