introspect vs speculate

introspect and speculate both are verbs.

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

As verbs, speculate is a hypernym of introspect; that is, speculate is a word with a broader meaning than introspect:

Other hypernyms of introspect include chew over, contemplate, excogitate, meditate, mull, mull over, muse, ponder, reflect, ruminate, think over.

introspect (verb)	speculate (verb)
reflect on one's own thoughts and feelings	reflect deeply on a subject
	to believe especially on uncertain or tentative grounds
	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