Dear Readers, Has the stock market gotten too predictable for you? Indexes have hovered near record highs for months, and it's been the usual suspects driving moves: stimulus updates, economic-growth prospects, regulation and tax concerns, and maybe a dash of company earnings here and there. Those looking for a little more excitement would be well-advised to look towards cryptocurrencies, which are constantly rewriting the record book amid unprecedented volatility. Bitcoin in particular has been on a wild ride, with prices fluctuating by up to $5,000 per unit on any given day. New record high...