https://www.reuters.com/article/us-crypto-currency-altcoins/buyers-beware-as-altcoin-frenzy-bruises-bitcoin-idUSKCN2CZ1N6 >Bitcoin's smaller rivals are eroding its share of the $2 trillion digital currency market. Of the dozens snapping at its heels, most have little use beyond financial trading - but few of the investors fuelling their rise seem bothered.