IPO vs initial public offering

IPO and initial public offering both are nouns.

Word	Noun	Adjective	Verb	Adverb
IPO	Yes	No	No	No
initial public offering	Yes	No	No	No

As nouns, IPO and initial public offering are synonyms defined as:

IPO and initial public offering: a corporation's first offer to sell stock to the public

Other synonyms of IPO include initial offering.

IPO (noun)	initial public offering (noun)
a corporation's first offer to sell stock to the public	a corporation's first offer to sell stock to the public