Absolutely. It is the digital version of a gold dealer where you go to exchange your currency for local money. Imagine you travel to Vietnam, you can get local currency from your ATM and get a terrible rate... or you can take USD to a gold dealer and buy the local currency "on the black market". They give you a rate, take a cut, use it to hedge against their gold. Almost always a better rate than the banks.

Now it is happening online for people who want to say switch between various ETH tokens. This is what DeFi is all about. $20b is locked up into this stuff already and growing. Things are moving insanely fast.

If you want to dip into the more regulated version (CeFi), take a look at BlockFi or Celsius.