My understanding was that before 12/31/2017, if you made money by increasing your bitcoins from trading alt coins that you could try to utliize the "like-kind" clause which does not force you report a tax on that trade.
For example, if I make 3 BTC in profit from trading alt coins against BTC in 2017, then does my BTC profit count as a taxable event if I never cashed out?
the IRS has never officially commented on cryptocurrency and like-kind exchanges. re tax years 2017 and prior it's still a grey area, although i've heard many tax advisors
taking the cautious route and assuming that different cryptocurrencies don't qualify as "like-kind". it's possible the 2018 tax code just made the restriction explicit.
which exchanges did you use? coinbase, i assume? they may not have much on you beyond your coinbase data.