If you plan on day trading "virtual currency" the IRS has found a way to screw you over. The new tax bill that went into affect January 1, 2018, is no longer treating cryptocurrency like stocks and bonds. It used to be that you would have to pay taxes on any cash profit you make. So if you put in $1000 into crypto and double your money, when you cash it you would pay capital gain taxes on that $1000, plain and simple. The new law complicates things by taxing any transaction including trades. This also includes buying, selling, transferring, and receiving crypto. Day traders make pronoun amounts of trades in just one day. These laws make it nearly impossible to calculate every transaction that has taken place over the year. (This is not legal advice) Moving forward you can either keep better records of your trades, or just ignore the law and later pay the consciences if caught.
This can seem like an attack on the crypto market, in reality I see it as a stabilization for the future of cryptocurrency. These tax codes are going to force people to hold on to their coins for the long term and prevent all those big pump and dump schemes from happening.
http://bitcoinist.com/cryptocurrency-investors-lose-tax-break/