Meaning

noun someone who makes conjectures without knowing the facts

noun someone who risks losses for the possibility of considerable gains

originFrom Latin speculātor (“spy, explorer, investigator”), from speculor (“to watch, to observe”) + -tor (“-er: forming agent nouns”), from specula (“watchtower”), from speciō (“to watch, to observe”), q.v. In some senses, an agent noun formed within English from speculate. Doublet of spectator.

Etymology from Wiktionary, CC BY-SA 3.0