Note - CoinLedger does not currently support the taxation treatment of margin trades.
Update 7/27/2020 - Poloniex is closed to U.S. customers
Login To Your Poloniex Account
Select "Activity" from the upper-right corner
Select the "Trades", "Deposits" or "Withdrawals" option and export your corresponding history using Poloniex's date ranges.
(You may have to export multiple files to capture all of your history. Please make sure dates do not overlap to avoid duplicate trades).
DO NOT open the file in Excel and "save as" a new file.
It's important to upload the raw file that Poloniex exports straight from your "Downloads" folder. This avoids rounding errors and corrupting the file. If you need to edit your CSV, please use Google Sheets.
You will receive a file in .csv format. Navigate to Step 1. Import. Select Add Account then choose the Poloniex tab on CoinLedger. Click on Upload File and drag your CSV file into the box to import your transactions.