Understood and thanks. So, if I install a brand new browser and use that for nothing but my online-banking I should be reasonably safe?
Yes.
I am wondering can we have two or multiple firefoxes or Google Chrome on the same system? I am going to find out :-)
You can. In many cases, the browsers support multiple profiles, as MarkMLI has mentioned.
Any option that gets you isolation from shared cookies or shared extensions will be helpful.