It's no secret, I do not like Bitcoin. I see it as an incredibly risky investment, a fiscal train wreck that is inevitable.
Nonetheless, some people are sitting on impressive gains, and looking for ways to minimize the tax bite. Some are looking to §1031, which deals with like-kind exchanges. The theory is, if you exchange your grossly appreciated Bitcoin for a similar property, like Etherium or Litecoin, you could defer recognizing taxable gain until you dispose of the replacement property.
I don't think this theory will work, because I don't think cryptocurrency fits into §1031. A number of experts agree with me. The IRS has not issued any guidance on this issue. However, if you are inclined to try this ploy (penalties and interest may apply), you only have a few days to make it happen. The pending tax reform bill makes it clear that §1031 applies to real estate transactions, only.
How's this for a nightmare scenario? You race to exchange one crypto for another, before Tax Reform takes effect. The IRS later pronounces that §1031 does NOT apply, so it turns out you have a massive taxable gain for 2017. But wait, early in 2018, all cryptos crash, giving you an equally massive capital loss, of which you can deduct only $3,000 per year for the next 100 years. But hey, if you were not a gambler you wouldn't own this stuff in the first place!