acumen vs shrewdness

acumen and shrewdness both are nouns.

Word	Noun	Adjective	Verb	Adverb
acumen	Yes	No	No	No
shrewdness	Yes	No	No	No

As nouns, shrewdness is a hypernym of acumen; that is, shrewdness is a word with a broader meaning than acumen:

acumen: shrewdness shown by keen insight
shrewdness: intelligence manifested by being astute (as in business dealings)

Other hypernyms of acumen include astuteness, perspicaciousness, perspicacity.

acumen (noun)	shrewdness (noun)
shrewdness shown by keen insight	intelligence manifested by being astute (as in business dealings)
a tapering point