A lot of exchanges now allow you to store your currency as well as exchange it. You can then swap it internally for other kinds of cryptocurrency. You can follow the activity of your currency – it’s fluctuations in value and get values of one currency against the others or against your original purchase currency.
Again, we like Coinbase for this. It’s an exchange/wallet combination that lets you buy in multiple currencies and swap your assets between many different cryptocurrency.
YoBit Is based on trading pairs with Ethereum if you have those coins.
Gate Blockchain Assets Trading Platform low trading fees and cold storage
Changelly Best place to buy Bitcoin with your credit card.
CoinMama Another way to buy Bitcoin or Ethereum with your credit card.
HitBTC is the most advanced Bitcoin exchange for the expert trader.
Cryptopia has many altcoins for you to trade with reasonable fees.