commerce vs trade in

commerce is a noun but trade in is not a noun.

Word	Noun	Adjective	Verb	Adverb
commerce	Yes	No	No	No
trade in	No	No	Yes	No

commerce (noun)	trade in (noun)
transactions (sales and purchases) having the objective of supplying commodities (goods and services)
social exchange, especially of opinions, attitudes, etc.

commerce (verb)	trade in (verb)
	turn in as payment or part payment for a purchase