If i'm not mistaken, SegWit2x proponents never said it's fully cancelled, just postponed. This means that there is a theoretical possibility that they might try to pull it off again somewhere in future. So what is traded now are futures. Here is the definition of futures
https://www.investopedia.com/terms/f/futures.aspNo, that's not what it is. If they try again, it won't be at Block Height 494784. That's important in this case.
I believe that most of the B2X futures contracts are based on Bitfinex's model. Specifically, the Segwit2x coin split contracts do not give you delivery rights on any fork in the future besides Segwit2x.
They define Segwit2x very clearly:
1.4 “Chain Split Event” means a fork in the Incumbent Bitcoin Blockchain that produces a viable and alternative blockchain based on—and that may only be used exclusively based on—the consensus protocol of Segwit2x. Segwit2x is scheduled to occur at Block Height 494784 and will be deemed to occur at the moment in time that a new, viable, and exclusive blockchain based on the Segwit2x consensus protocol comes into existence
1.9 “Segwit2x” means the anticipated Bitcoin blockchain that will be exclusively used based on the consensus protocol as set out from time to time in the repository
https://github.com/btc1/bitcoinSo B2X delivery is based on the btc1 repository (Garzik and company), which was scheduled to occur at Block Height 494784. As it turns out, there was an existential flaw in the btc1 consensus code caused by an off-by-one error which
caused btc1 nodes to freeze permanently at Block Height 494782:
While Bitcoin and SegWit2x nodes were widely expected to share a single blockchain up until block 494783 and then to go their own ways at block 494784, btc1 nodes never made it past block 494782.
This is mainly because the first block on the SegWit2x chain was required to have a “base block” larger than one megabyte. This is how the chain would diverge from the original Bitcoin protocol. But due to what is referred to as an “off-by-one error,” SegWit2x blocks started to reject smaller-than-one-megabyte blocks one block too soon — at block 494,783 instead of 494,784.
So B2X futures are in a perpetually stuck state. We all know there will never be delivery. The implementation was broken and no rational miners would mine it at this point.
But it's
theoretically possible that the btc1 code could be fixed. Then the fork could occur based on a blockchain snapshot at block 494783. At that point, exchanges could convert BT2 (or equivalent) to B2X. I think that's technically why B2X tokens are still traded...
