Since spot ETFs listed options, BTC and ETH each sit under two independent books with different multipliers, hours, expiries and participants — set out in IBIT is not Bitcoin.
That article makes the negative case: do not mix them. This is the positive one.
What each book is telling you
The crypto-native book is global, continuous, and call-heavy — positioning from participants expressing upside around the clock.
The ETF book is US-hours, accessed through brokerage accounts, and closer to equity conventions in who trades it and why. It is far more likely to carry protective put buying, because the holders are the sort who hedge.
The disagreement is the signal
When the two skews point different ways, that is not an error to resolve. It says the two participant groups have different views — and since one is largely US institutional and the other is global and continuous, that difference is worth knowing.
The naive response is to average them, which is the same category error as blending funding across venues: the composite describes nobody.
Two clocks, one asset
The ETF book stops hedging at the US close and the crypto book does not. So overnight moves are hedged in one market only, and the ETF complex arrives in the morning to catch up — a gap that is a catch-up rather than a signal, the same structure as ETF creation flow.
The practical method
Compute per book, label every figure with the book it came from, and read the pair. Never sum them, never average their levels, and never plot one against the other’s underlying.