underwriter vs investment banker

underwriter and investment banker both are nouns.

Word	Noun	Adjective	Verb	Adverb
underwriter	Yes	No	No	No
investment banker	Yes	No	No	No

As nouns, underwriter and investment banker are synonyms defined as:

underwriter and investment banker: a banker who deals chiefly in underwriting new securities

underwriter (noun)	investment banker (noun)
a financial institution that sells insurance	a banker who deals chiefly in underwriting new securities
a banker who deals chiefly in underwriting new securities
an agent who sells insurance