Source : Webster's Revised Unabridged Dictionary (1913)

Speculator \Spec"u*la`tor\, n. [L., a spy, explorer,
   investigator: cf. F. sp['e]culateur.]
   One who speculates. Specifically:
   (a) An observer; a contemplator; hence, a spy; a watcher.
       [Obs.] --Sir T. Browne.
   (b) One who forms theories; a theorist.

             A speculator who had dared to affirm that the human
             soul is by nature mortal.            --Macaulay.
   (c) (Com.) One who engages in speculation; one who buys and
       sells goods, land, etc., with the expectation of deriving
       profit from fluctuations in price.

Source : WordNet®

speculator
     n 1: someone who makes conjectures without knowing the facts
     2: someone who risks losses for the possibility of considerable
        gains [syn: {plunger}]