ETYM Latin, a spy, explorer, investigator: cf. French spéculateur.
Individual or business that buys and sells in the hope of making a quick profit. On the stock market, for example, speculators might buy a share in the hope that it will quickly rise in price so that they can then sell it at a profit.
1. Someone who makes conjectures without knowing the facts.
2. Someone who risks losses for the possibility of considerable gains; SYN. plunger.