[metellus]

  > Co-founders Jerry Guo and Michael Waxman like to joke
  > that Grouper is a Y Combinator-funded startup.

They're not actually claiming to be funded by Y Combinator. Betabeat's headline didn't mention YC either.

[biot]

The HN title used to be: "YC-Funded Despite Rejection". It has since been updated to match the Betabeat headline.