The two companies conspired to cause the value of the stock to fall.
Examples of conspire
conspire
We do not want separatists, divisionists, people who conspire against the unity.
From the edition.cnn.com
Two or three stars can conspire, work the system and create their own superteam.
From the sfgate.com
But the physics conspire against it keeping pace with other $100K sports sedans.
From the techcrunch.com
Serb leaders from both sides of the Danube began to conspire against the dahias.
From the en.wikipedia.org
Its tough when the eighteenth-century engineering starts to conspire against you.
From the guardian.co.uk
The Britons will certainly loathe it and, what is worse, may conspire against it.
From the economist.com
Unless my feet conspire against me again, I won't be one of them any time soon.
From the delawareonline.com
So why should the government conspire with official Catholicism to thwart them?
From the suntimes.com
They conspire with politicians and journalists to conceal this from the public.
From the post-gazette.com
More examples
Engage in plotting or enter into a conspiracy, swear together; "They conspired to overthrow the government"
Act in unison or agreement and in secret towards a deceitful or illegal purpose; "The two companies conspired to cause the value of the stock to fall"
To secretly plot or make plans together, often used regarding something bad or illegal; To agree, to concur to one end; To try to make things go a certain way
(conspiring) conspiracy
A keyword ability that creates a copy of a spell. See rule 702.75, "Conspire."
To plan together secretly to do something (wrong)
As a player casts a spell with conspire, he or she may pay the optional, additional cost of tapping two creatures that share a color with the spell. He or she then copies the spell and may choose new targets for the copy. Conspire appears on instants and sorceries in Shadowmoor.