Investing.com - European Union regulators issued a scathing assessment of cryptocurrencies Monday, saying they show signs of a price bubble and are unsuitable for investment.The warning came in a joint statement from banking, securities and insurance regulators at the request of a top European Commission official.E.U. regulators are the latest to express concerns about the safety of investing in bitcoin and other cryptocurrencies, which have slumped badly in recent weeks on growing fears of a regulatory crackdown in China, South Korea and India. The E.U. regulators said cryptocurrencies are subject to extreme price volatility, and are so risky that investors should be prepared to lose most or even all of their money.The statement is a sign regulators in Europe are considering efforts to reign in the digital currencies, following previous concerns about their role in money laundering and terrorism funding.France and Germany, the E.U.'s two biggest members, are working on a set of regulatory proposals that they plan to present to the Group of 20 nations at its meeting in March.