equity research interview at UBS/CS/BAML

Hey Guys,

Long time reader but first time poster. I have a first round interview coming up in ER and am wondering how best to prepare. I have read vault guides and prepared for general finance/behavioural questions. I've heard a lot about the stock pitch. I am wondering whether it is expected that I have this prepared for first round or if this is something that is more typically asked during later rounds of interviews. If anyone could shed some knowledge on this I would really appreciate your help!!

A bit of background. I graduated from a target and currently work at a BB in corporate banking.

Thanks again!!