Speculator

An inexperienced stock speculator could easily let his business go to pot and lose his entire fortune.

If someone, because of his love of a forest, walks there half of every day, he is in danger of being regarded as a loafer; but if he spends his whole day as a speculator, chopping down that forest and making the earth bald before its time, he is esteemed an industrious and enterprising citizen.

a bold and paradoxical speculator

[…] in things of Fact, the People are as much to be believed, as the most subtle Philosophers and Speculators, since here sense is the Judge.

For, in the earlier part of the seventeenth century, a speculator who had dared to affirm that the human soul is by its nature mortal, and does, in the great majority of cases, actually die with the body, would have been burned alive in Smithfield.