Can Someone Explain How Bitcoin ETFs Work?

I guess I kind of naively expected a share of an ETF to be the same price as a bitcoin, but so many prices!. Each ETF has a different scale somehow. Or maybe they aren't attached to bitcoin at all?! And note that bitcoin's percentage price drop for the day is much different from those in the ETFs.

I've been digging for a few hours and I got nothin! I went to 3 different ETF pages and I don't see much assurance that they buy bitcoin in equal amounts to their price. Only VanEck literally mentioned they buy bitcoin at all! Other ETFs have mentioned keeping custody at Coinbase, but the skeptic in me would like them to say straightforward that they custody in proportion to the price of the bitcoin.

Here's an example of the confusion. Greyscale actually mentioned they have "bitcoins per share." But that value is 0.00089386 bitcoins per share. That's a weird number. If that would have been 0.001, then they would have 1000 bitcoins per share. But their number implies they have about 1119 bitcoins per share. I could watch this for a few months and see if that changes, but I'd really like to know how it works without guessing based on months of collecting data.

Anyone, knowledgeable interested in explaining a bit?