That doesn't really mean anything, speaking as someone who also interviewed for YC recently. It could just be a confluence of ideas, or that your product isn't really that unique. It doesn't mean they're "stealing" ideas, and even if they are, so what? It's gonna happen as soon as you go to market, so you're gonna have to deal with it sometime. More likely, though, is that no one will actually give a shit about your product and you have to beg them to care, which is what YC themselves say.
Possible. But batches are relatively small. When you see a copycat appearing in the same batch of your interview (and interview was a not a direct reject, there were follow up calls).
There is a difference between “an idea” versus investment of a few months of prototyping and market research that goes into distilling an approach to a product.
You can simply multiply going salary of the professional that us doing it onto the time spent. And then get a rough estimate of the value of that IP.
When a startup goes to a VC there is inevitably a transfer of that IP to the VC. And the transfer is unidirectional, until a partner invests their capital and time.
