Why not bitcoin? Did you ever see anybody market it? Hell no. It has got a community of its own and a userbase supporting it in every bad day. What it shows is that is a product is having its use case and solves a real problem, it will need the least marketing and be able to grow on its own.

Then we have these shit coins that claim to be prepared hat not, but end up as a disappointment in the long run.

So my hidden gem is never hidden because it is bitcoin bought at low price.