Investing.com - Wall Street may be interested in cryptocurrencies, after all.One in five financial firms are considering trading digital currencies in the next three to 12 months, according to a new survey. Thomson Reuters surveyed some 400 of its client firms, from hedge funds to asset managers to bank trading desks, saying the results were a major change from last year. Of the firms considering trading, 70% said they were looking at a time frame of three to six months. Another 22% said trading could start in six to 12 months. Thomson Reuters said the results show the cryptocurrency niche market is starting to enter the mainstream.Bitcoin and other cryptocurrencies have rallied over the past month, following a deep slump that began in late January.