> For the complete documentation index, see [llms.txt](https://help.mystocksportfolio.app/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.mystocksportfolio.app/help-guide/multi-currency-portfolios/forex-rate-at-time-of-transaction.md).

# Forex rate at time of transaction

When you add or edit a transaction, there is a purchase exchange rate override field for setting the forex rate at time of purchase. You can set this field to take into account currency fluctuations.

If you leave this field blank, we will use the current forex rate. To lookup historical forex rates, you can query for the forex symbol, such as USDCAD=X for United States Dollar to Canadian Dollar forex rate.