Cryptocurrencies or digital currencies, which are not issued by a president or government, nor by a central bank like any common currency.
The price of cryptocurrencies is dictated by other types of variables, particularly the market capitalization, the volume of operation and the supply-demand of it. therefore this currency has much more value than the others and this is the time to invest because in a few years it may be worth hundreds of thousands of euros and you don't want to lose it, right?
Digital currencies such as: Stellar, Nem. Dash, Ripple, Golem, Litecoin, Cardano, Tether, Monero, Zcash, Bytecoin, Ziliqa, Ontology, Maker, Steem, Dogecoin, Augur, Bitcoin Diamond, Waves, Stratis, Status, One Coin, among others. They are names to consider to be studied in case you want to invest.