I would say that "blockchain", as a concept, isn't a suitable category, in the same way that "mobile application" or "website" isn't.

Blockchain is a tool. The applications are varied. There are potential applications for blockchain technologies in each of the rfs categories.

Thank you for this answer. It makes a lot of sense. I suppose I was conflating blockchain technology with actual problems that it could solve. The same probably also applies to cryptocurrency.

The RFS isn't meant to be an exhaustive list of the ideas we're interested in funding. It's a list of ideas we'd like even more founders to apply with. We get a lot of blockchain and crypto applications -- and if that's what you're working on, I recommend you apply with it.

Lots of things are absent from the list. The list isn't what YC is willing to fund-- it's what YC wants to encourage people to start thinking about if they don't already have ideas for a not-so-bloated space.

Yes