Are you summing the opportunity amounts in JS?   If you can use the currency field renderer you should get commas.  Otherwise if you are just injecting a field value - you may need to parse the number and add commas. 

If you use an aggregate model you can simply use field merge syntax - that will correct include the currency renderer. 

Can you elaborate on this, Rob? I’m using an aggregate model and a UI only formula field to display a currency value in a rich text component - and (luckily) we need some commas. 

Figured it out. formula output as a number value. triple curly brackets in the UI only formula field, double curly brackets in the rich text component.

Way to go…