I understand perfectly well about being long in BTC and receiving B2X tokens (read you have bitcoins in your account), but I don't quite understand the part between the parts you made bold. In other words, the quote you posted could be read as "Users that are financed [...] short any BTC trading pair will receive B2X". Doesn't it contradict the parts which are bold in your post since you can be short or long BTC in "any BTC trading pair"? This makes no sense to me. If I read it literally, it basically means that both lenders and borrowers should be credited B2X coins which is nonsense, obviously. What am I missing here or is it just Bitfinex not being quite clear in their statement?
It's just that Bitfinex list the other currency pairs the other way round. So being long BTCUSD means you borrowed USD to buy BTC. Being short ETHBTC means you borrow ETH to buy BTC. In both cases, you did not borrow the BTC and therefore own it and get the split token.
It would be simpler to understand if exchanges always listed BTC is the first currency. If they called it BTCETH then the example I just gave would also be a long trade. I have no idea why they don't do it that way
An idea has just struck me
It makes sense to lend your bitcoins (so that you get B2X tokens) and at the same time short the same amount of bitcoins. By lending and borrowing, you will 1) receive some percentage spread (since you can lend at higher rates and borrow at lower, it is pretty easy to do) and 2) protect yourself from any price crash if that should happen due to the hard fork while still receiving the B2X tokens, which you can sell at any time you deem right. Anyone want to comment on this?