Key takeaways: Cryptocurrencies are incredibly volatile and not for all investors. Decide if they fit your risk tolerance before diving in. Bitcoin and Ether are in a league of their own as the two best cryptocurrencies to buy. Four more speculative cryptos are worth a look, each with their own defining characteristics. In a span of just 15 years, cryptocurrencies emerged from obscurity to become an important part of financial markets. But there's one thing the industry's evolution hasn't eradicated: extreme volatility.At its peak in November 2021, the crypto market...