be sitting on a gold mine(redirected from was sitting on a goldmine)
be sitting on a gold mine
To have immediate access to a plentiful amount of something valuable or desirable, especially something that one has not yet profited from. Who knew that my grandfather was sitting on a gold mine of priceless antiques all these years? If your social networking site is attracting millions of new users every month, then you guys are definitely sitting on a gold mine.