An amazing amount of misinformation on this thread. I'm answering for the US. I don't know about other countries.
Of course you have to pay taxes on your profits in cryptocurrencies. This is well established.
Whether you have to pay taxes on exchanges of one cryptocurrency for another depends on whether such transactions can be claimed as "like kind" transactions. Whether "like kind" applies to exchanges between cryptocurrencies is controversial. I think that the IRS will eventually rule that these transactions are _not_ like kind and I've read extensively on the issue. Others disagree.
If you choose to treat exchanges between cryptocurrencies as like kind transactions you have to declare them as such on IRS form 8824! Absolutely everyone who trades cryptocurrencies ignores this (except me, of course).
If the IRS rules that these transactions are not like kind, and you have filed form 8824, you are likely to be OK except that you will owe taxes, interest, and possibly penalties. If you haven't filed form 8824 I wouldn't want to be you.
Not a lawyer - just my well researched opinion.
You are rite about we need to pay tax but IRS Form 8824 that is not compulsorily we can report taxes and we need to report taxes, IRS recognize Bitcoin and crypto currencies as property so which will come on Capital Gain and loss which occurs in each and every transaction so if we trade that with any other alt coin and we make some btc than profit btc should converted in USD for that day and calculated tax to report. Each and every transaction profit and loss record should be kept if IRS finds some error they might need that
For me that didn't happen yetVery simple Understanding is If you buy your car in 1200 and sell in 1900 you have to pay Tax for 700 because it is more than 600$, You have to pay each and every capital gain which exceed $600 in a fiscal year.