means The act of forming an opinion or making a financial bet without solid evidence, gambling on what might happen rather than what is known.

from From Latin speculari, 'to spy out, watch, or observe,' which comes from specula, 'a watchtower,' and ultimately specere, 'to look.' The same root that gives us spectacle and inspect once meant a literal lookout scanning the horizon — and that's exactly what speculation still is: peering into the distance, trying to glimpse a future you cannot yet see. By the time the word reached finance, the watchtower had become the trading floor, the horizon had become tomorrow's price, and the watchman had started placing bets on what he thought he saw.