[WJW]

Well stablecoins by design cannot really fluctuate a lot in value (unless they collapse), so speculation on them is pretty much out.

It's still pretty unclear to me why you'd actually want a blockchain for managing it though, rather than a traditional database hosted by the central bank that is responsible for the currency that the stablecoin is following. You'd get vastly more throughput at much lower costs, and it's not like you really need decentralization for such a system anyway. The stablecoin is backed by something the central bank already has authority over.

[galenmarchetti]

then why hasn't the central bank done this yet

[WJW]

Depends. Several central banks are working on exactly that, see for example the recent speech by the FED and the whole GENIUS act regulation framework.

But to be honest where I am (northwest Europe) we already have subsecond person-to-person transactions via the normal banking system, no matter which bank the sender and receiver use. So stablecoin-ifying the Euro wouldn't make a huge difference. There might be more to gain if the region doesn't have that kind of payment infrastructure yet.