iFrame permalinks on WordPress

What you want is not possible.

The iframe on your page is generated by a script from WebLink that requires the ?symbol= parameter in the URL to be able to generate the correct iframe.

If you rewrote the URL the way you want the script would not work, since the symbol parameter doesn’t exist anymore. WordPress would be able to access the value, but the script would not see it anymore, and it’s the script that creates the iframe.

You will need to check with WebLink to see if it’s possible to set the stock symbol for the iframe a different way.