When you buy a coin/token in a token sale, you want to make sure that you have a single transaction showing the purchase of the coin/token with two sides:
• Sent: what you paid for the coin/token • Received: the amount of the coin/token that you received
Let's say you are participating in a 0x (ZRX) token sale where you paid 5 ETH for 2,500 ZRX. Once you sync your ETH wallet(s), you should see something like the following:
Note: these two transactions could be one right after another or months apart. The could also be to the same wallet or different wallets.
To tie these together, edit the Sent transaction using the dropdown on the right side of the transaction as so:
Essentially copying the information about the received token, including the quantity, the symbol, and the wallet. Update the transaction.
The result should be one trade showing the payment and the received token with the appropriate capital gain. Don't forget to ignore the originally synced transaction (which is now duplicated):
Note: the originally synced send transaction will also be greyed out and struck through which is fine (this is left in case you need to revert your transactions in the future)