Broadcasters have long said Aereo violates copyright law and threatens their business by distributing their signals without paying them.
Investors responded to the court decision.
In midsession trading Wednesday, shares of Hunt Valley, Md.-based Sinclair Broadcasting Group Inc. surged $4.26, or 14.6%, to $33.50 a share on the Nasdaq stock exchange. Nextstar Broadcasting Group, headquartered in Irving, Texas, jumped $6.82, or nearly 16%, to $49.83 a share.
Shares in CBS Corp., which has been especially vocal in the fight against Aereo, were up $2.48, more than 4%, to $61.31.
Aereo, founded in 2012 and available in 11 markets, charges customers between $8 and $12 a month for its service that includes a cloud-based digital video recorder. It argued to the high court that its service did not violate the Copyright Act, claiming that it acted as an antenna service rather than a cable company.
The court disagreed and ruled against Aereo in a 6-3 decision, overturning a lower court ruling.
Marci Ryvicker, a senior analyst at Wells Fargo who covers the media and cable industries, said the decision was "clearly a positive."
In a note to clients, Ryvicker said the ruling was not a surprise. "We continue to like the broadcast group and diversifieds," Ryvicker said.
Follow Ryan Faughnder on Twitter: @rfaughnder