For pipeline reports - which currency exchange rate is used?

It’s the rate at the date of the transaction being created. When I looked into that over a year ago, we discovered the report does not update to reflect todays rate. For example, Quote generated for USD within Jan 2018. Reflects the value at that date, even when running now in June 2018. We discovered it when the exchange rates were drastically changing between Euro and USD . They only way to update the rates is to edit each transaction. A simple, edit and save triggered the update.