Collocations for speculation - noun

considerable, intense, much, widespread
further, increasing, renewed
continuing (esp. BrE), endless
recent
pure
mere, sheer
Whether or not he will get the job is mere speculation.

wild
media, press
metaphysical, philosophical

cause, encourage, fuel, give rise to, increase, intensify, invite, lead to, prompt, raise
dampen (esp. BrE), dismiss, quash (esp. BrE)
end, put an end to
confirm
indulge in

be rife, run rampant (esp. AmE)
Speculation was rife as to who would be chosen as a successor.
With a lack of credible answers, speculation is running rampant.

grow, mount
Speculation is mounting that a new tax will be introduced.

centre/center on, surround
Much speculation surrounds his role in the crisis.

be based on
amateur speculation based on questionable assumptions

link (esp. BrE)
There has been a lot of speculation linking the defender with a move to Chelsea.

amid speculation
He was dropped from the team amid speculation that he was sick.

speculation among
This issue has attracted a great deal of speculation among economists.
There was wild speculation among the students as to the reason for postponing the lecture.

speculation about, speculation as to, speculation on, speculation over
There has been increasing speculation over the company's future.

a matter for speculation (esp. BrE), a matter of speculation, a subject of speculation
speculation on sb's part
This is just speculation on my part.

financial
market, stock-market (esp. AmE)
currency, land, property (esp. BrE), real estate (AmE), etc.

speculation in
speculation in oil

speculation on
speculation on the stock market