This article has information about the limitations of different exchange API's. If you have negative balances in your wallets after a sync then it could be due to one of these issues.
- Binance airdrops can not be synced. You need to manually import these transactions. A helpful guide is provided here: https://support.koinly.io/hc/en-gb/articles/360001515338-How-to-quickly-import-Binance-airdrops
- Delisted tokens can not be synced. If you had trades in a currency that is no longer supported by Binance, you will need to import them manually or via csv. The list at the time of writing includes the following:
CLOAK, MOD, SALT, SUB, WINGS, BCN, CHAT, ICN, TRIG, CTR, LRCVisit https://binance.zendesk.com/hc/en-us/search?utf8=%E2%9C%93&query=delist to find an up to date list of delisted tokens.
- Only deposits after 1/1/2019 or the last 100 deposits can be synced. If you find that you have negative balances after the sync, you should import the transactions for Bittrex using the File importer.
- It looks like Bitstamp might have suffered some data loss between Feb 2018 and March 2018, so trades around these times may not be imported. You will need to add the missing trades manually or via csv.