theorize vs speculate

theorize and speculate both are verbs.

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

As verbs, theorize and speculate are synonyms defined as:

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

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

theorize (verb)	speculate (verb)
to believe especially on uncertain or tentative grounds	reflect deeply on a subject
form or construct theories	to believe especially on uncertain or tentative grounds
construct a theory about	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
	invest at a risk