https://www.bloomberg.com/news/articles/2017-12-06/this-little-known-tax-proposal-takes-aim-at-your-trading-account
I think there are ways you can circumvent this new rule. I´m not from the US so take my advice with a grain of salt, but
in my country it is possible to circumvent this by using "layers". By this I mean separate trading accounts (or wallets
in the case of BTC) where you can easily prove that the stocks/coins had a different investment purpose.
E.g. you could have a long-term investment hardware wallet and a short term trading wallet. If you sell coins from
the short term trading wallet it is irrelevant if you still have "older" (=bought earlier) coins in the long-term investment wallet.
The financial authorities accept this kind of structure even though FIFO is generally the standard.
Of course you have to stick to this method once you start to declare this way, it is not possible to use "layers" when it suits
you and FIFO when it suits you better.
On an unrelated note, Bithumb is going crazy right now. BTC is trading for nearly 18k $, which would make
for a really nice arbitrage opportunity if you are able to setup a Korean exchange account.