With new “coins” cropping up all the time, it’s hard to keep track of what’s worth paying attention to and what might not be here to stay.Meanwhile, major companies are jumping on the bandwagon: Tesla announced earlier this year that customers may buy vehicles with bitcoin. Digital payment platform Square (SQ) and PayPal (PYPL), which also owns transfer app Venmo, now also allow customers to use cryptos.Ranked by their market capitalization in US dollars, the biggest cryptocurrencies in the world