exponential return vs exponential decay

exponential return and exponential decay both are nouns.

Word	Noun	Adjective	Verb	Adverb
exponential return	Yes	No	No	No
exponential decay	Yes	No	No	No

As nouns, exponential return and exponential decay are synonyms defined as:

exponential return and exponential decay: a decrease that follows an exponential function

exponential return (noun)	exponential decay (noun)
a decrease that follows an exponential function	a decrease that follows an exponential function