speculate vs theorize

speculate and theorize both are verbs.

Word	Noun	Adjective	Verb	Adverb
speculate	No	No	Yes	No
theorize	No	No	Yes	No

As verbs, speculate and theorize are synonyms defined as:

speculate and theorize: to believe especially on uncertain or tentative grounds

Other synonyms of speculate include conjecture, hypothecate, hypothesise, hypothesize, suppose, theorise.

speculate (verb)	theorize (verb)
reflect deeply on a subject	to believe especially on uncertain or tentative grounds
to believe especially on uncertain or tentative grounds	form or construct theories
talk over conjecturally, or review in an idle or casual way and with an element of doubt or without sufficient reason to reach a conclusion	construct a theory about
invest at a risk