Cost basis of trades
We can only provide trade information for the two currencies directly involved in your trade (i.e. the base currency and the quote currency).
Your cost basis is technically in the quote currency that was used in the transaction.
If you want to know the cash (USD/EUR/CAD) cost basis of a trade that doesn't involve that currency, you'll have to estimate this yourself based on historical market rates.
Tip: remember to include trading fees (if any) in the cost basis calculation.
Cost basis of deposits
There's no way for us to know the cost basis of cryptocurrencies deposited to Kraken.
You will need to find or estimate the value of the cryptocurrency from the place and date you originally obtained it.
Disclaimer
IMPORTANT: Countries differ on how cryptocurrency transactions, trades, and holdings are taxed (if at all) and how they view cryptocurrencies in general (e.g. as money, as property, as a commodity, etc). Please consult a local accountant, tax lawyer, and/or government official for advice.