If you think about it, Bitcoin is the King of all of it because everything is basically a FORK and main idea from BTC.
Even if it other cryptocurrencies are not forks, it was thought the same way as Bitcoin.
To work just as him, on a regular basis, pure network transactions, decentralized / centralized, using an address.
All of that makes that cryptocurrency tradeable but with different price from Bitcoin.
Not only that but all other currencies that followed BTC closely want to reuse his base technology for several new others.