speculate on (something)

speculate on (something)

To conjecture, hypothesize, or make guesses about something without having supporting or conclusive evidence. You can't just speculate on what effect this legislation will have on the country—you've got to have some concrete data to show it will work! Instead of spending your energy speculating on the future, you should focus on the present and do what makes you happy.
See also: on, speculate

speculate in something

to make risky business deals in the buying and selling of something. Jeff made a fortune speculating in cotton. I do not wish to speculate in anything. It is too risky.
See also: speculate

speculate on something

to make a hypothesis about something. I really don't want to speculate on what might happen next. Would you care to speculate on what might happen if you quit your job?
See also: on, speculate