selloff vs sales event

selloff and sales event both are nouns.

Word	Noun	Adjective	Verb	Adverb
selloff	Yes	No	No	No
sales event	Yes	No	No	No

As nouns, sales event is a hypernym of selloff; that is, sales event is a word with a broader meaning than selloff:

selloff: a sale of a relatively large number of assets (stocks or bonds or commodities) at a low price typically done to dispose of them rather than as normal trade
sales event: an occasion (usually brief) for buying at specially reduced prices

Other hypernyms of selloff include cut-rate sale, sale.

selloff (noun)	sales event (noun)
a sale of a relatively large number of assets (stocks or bonds or commodities) at a low price typically done to dispose of them rather than as normal trade	an occasion (usually brief) for buying at specially reduced prices