DRW is a firm focusing on trading cryptocurrencies; the Chicago based firm has about a dozen employees working on crypto trading through a subsidiary called Cumberland Mining; there are several other firms operating in this area as well including Jump Trading, DV Trading and Hehmeyer Trading + Investments; volatility in other asset classes is low, making crypto an attractive asset class for these firms. Source
The high volatility in cryptocurrency prices has created an opportunity for high frequency traders looking for alternatives; the stock market has been steadily rising but their has rarely been a daily jump or drop of more than one percent; while there has no been wide adoption of the strategy more firms have begun trading in the space as the market cap continues to rise. Source.