speculator

noun

spec·​u·​la·​tor ˈspe-kyə-ˌlā-tər 

plural speculators

: someone who speculates: such as

a

: a person who thinks or guesses especially in an idle or casual way about something that is unknown or uncertain

I sat Friday night in the dining room in front of my laptop, the TV in the next room flitting among experts and speculators about what happened in Paris …

Scott Martelle

"… All that we ought to ask, therefore, is, that the witnesses of our conduct, and the speculators on our motives, should be capable of taking the highest view which the circumstances of the case may admit. …"

Nathaniel Hawthorne

b

: a person who makes a relatively risky investment in something (such as stocks or real estate) in the hope of making a large short-term profit from market fluctuations

futures/currency speculators

By the late 1870s Edward Pray was living in New York City, still interested in mining but instead now as a speculator in mining stocks.

Willa Kane

Over the years, many houses have been bought by speculators or real estate companies and rented out.

Margaret Gillerman

Word History

Etymology

speculate + -or entry 1; in earlier sense "observer, lookout," borrowed from Latin speculātor "scout, spy, sentinel," from speculārī "to keep a close watch on, spy out, watch for" + -tor, agent suffix — more at speculate

First Known Use

1555, in the meaning defined above