Translation of "speculator" into Chinese

The economy is too serious a matter to be left in the hands of speculators.

经济是非常严肃的,不能够任由投机者操纵。

One company in particular operated more as a land speculator than a builder of houses.

尤其是其中一家公司,从其经营手法来看,与其说它是建筑公司,还不如说它是地产投机商。