sum total vs accumulation

sum total and accumulation both are nouns.

Word	Noun	Adjective	Verb	Adverb
sum total	Yes	No	No	No
accumulation	Yes	No	No	No

As nouns, accumulation is a hypernym of sum total; that is, accumulation is a word with a broader meaning than sum total:

Other hypernyms of sum total include aggregation, assemblage, collection.

sum total (noun)	accumulation (noun)
the final aggregate	the act of accumulating
	several things grouped together or considered as a whole
	(finance) profits that are not paid out as dividends but are added to the capital base of the corporation
	an increase by natural growth or addition