Hey guys, I just stumbled upon this, great start, which addresses exchanges like shapeshifts etc:
https://www.reddit.com/r/Bitcoin/comments/1uccfz/i_am_a_tax_attorney_here_are_my_answers_to_the/?st=j5o6aew8&sh=8979a0b2#4: What if I exchange my bitcoins for altcoins? Is this a like-kind exchange?
This is a fair question and implicates what is known as a "like-kind exchange." Under Section 1031 of the tax code, exchanges of like-kind property do not trigger recognition of capital gains, and therefore are tax-free. Whether or not bitcoins/altoins are like-kind is uncertain to say the least. As intangible property, bitcoins/altcoins would qualify as like-kind only if they have the same rights, characteristics, and obligations. This is a very difficult test to apply to virtual currency.