speculate vs formulate

speculate and formulate both are verbs.

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

As verbs, formulate is a hyponym of speculate; that is, formulate is a word with a more specific, narrower meaning than speculate:

Other hyponyms of speculate include construct, reconstruct, retrace, develop, explicate.

speculate (verb)	formulate (verb)
reflect deeply on a subject	put into words or an expression
to believe especially on uncertain or tentative grounds	elaborate, as of theories and hypotheses
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	come up with (an idea, plan, explanation, theory, or principle) after a mental effort
invest at a risk	prepare according to a formula