I have a few transactions (listed below) converting from SGD to USD:-
2020-11-15 * "Purchase USD with SGD"
Assets:Equities:IBKR:USD 7848.00 USD @@ 10577.93 SGD
Expenses:Bills:BankCharges 2.00 USD
Assets:Equities:IBKR:USD -2.00 USD
Assets:Equities:IBKR:SGD -10577.93 SGD
2020-11-17 * "Purchase USD with SGD"
Assets:Equities:IBKR:USD 1.67 USD @@ 2.24 SGD
Assets:Equities:IBKR:SGD -2.24 SGD
2021-03-31 * "Purchase USD with SGD"
Assets:Equities:IBKR:USD 5524.00 USD @ 1.34495 SGD
Expenses:Bills:BankCharges 4.00 USD
Assets:Equities:IBKR:USD -4.00 USD
Assets:Equities:IBKR:SGD -7429.50 SGD
2021-04-05 * "Sweep remaining SGD to USD"
Assets:Equities:IBKR:SGD -0.22 SGD
Assets:Equities:IBKR:USD 0.1611 USD @ 1.34175 SGD
The 2020 transactions get "added" (debited, I think, not sure whether its a credit or debit) to Equity:Opening-Balances while the 2021 transactions get "added' to Equity:Conversions. I've read the 'Costs and Prices' section of the documentation, but it just says you can either use the price (@) or the total cost (@@), without really explaining what the difference is.
Could someone please help me understand why these go to different accounts, and what that 'means' in a financial sense?