The short version
A cryptocurrency is a digital asset whose ownership is recorded on a blockchain — a shared ledger maintained by many computers rather than by a single bank or company. Bitcoin, launched in 2009, was the first; there are now thousands.
Holding a cryptocurrency means controlling the keys that can move it on its ledger. Exchanges such as the ones in our platform directory let people buy and sell crypto, and many hold the keys on the customer's behalf.
Why prices move
Crypto prices are set by trading, around the clock, on many exchanges at once. There is no central closing price and no trading halt at night or at weekends.
Prices can swing sharply: daily moves of several percent are common, and larger moves happen. Supply and demand, news, regulation, liquidity and broader market sentiment all play a part.
Things to keep in mind
Crypto assets are generally not covered by deposit-insurance or investor-compensation schemes. Rules on who may offer crypto services differ by country.
Stablecoins aim to track a currency such as the US dollar; they are a different kind of asset from Bitcoin or Ether, with their own risks.