Can we name our company similar to a stock ticker?

Depends on how much you like getting tied up in legal disputes, I guess?

If you open "Mac & Donaldz burger grill" then you'd probably receive some not so polite notices from the golden arches.

If your name is McDonald and you run "McDonald Computer Consulting", then you still might get some grumpy lawyers chasing you.

Take a look at Monzo / Mondo, for example https://en.wikipedia.org/wiki/Monzo#History

Is that really how you want to start your company? Dealing with legal threats, whether baseless or not?