The tax rate depends on the length of time the cryptocurrency was held and your friend's income for the year. A 35% rate can be correct if the asset was held one year or less and your friend's gross income falls within the 35% bracket for his filing status.
Say you each put in $1,000 and the value skyrockets to $30,000. The transfer of your share is a taxable transaction for your friend and they owe taxes on the $9,000 gain from your share when you divvy up the cryptocurrency and collects the tax on that gain from you. He then transfers your share, which is worth $10,000 at the date of transfer. The transfer to you itself is not taxed.
Now, your cost basis for this cryptocurrency is $10,000 and your acquisition date is the date of the transfer. If you sell it a year or less from your acquisition date, then you will realize a short-term gain or loss based on your cost of $10,000. If you hold it longer than a year and realize a gain, your gain will be taxed at the preferential capital gains rate. It will still be calculated based on a $10,000 cost for the cryptocurrency when you received it in your wallet, not the $1,000 that you initially put in.
