Qualcomm shares closed the formal trading day up 2.2 percent to $56.60.
The jury in the U.S. District Court for the South District of California found that a number of iPhone models - the iPhone 7, iPhone 7 Plus, iPhone 8, iPhone 8 Plus, and iPhone X - infringed in varying degrees on three Qualcomm patents. There will be billions of dollars at stake in this case.
"Qualcomm's ongoing campaign of patent infringement claims is nothing more than an attempt to distract from the larger issues they face with investigations into their business practices in USA federal court, and around the world", an Apple statement notes.
A third patent related to promoting rich graphics in games while protecting battery life, according to Qualcomm. "The three patents found to be infringed in this case represent just a small fraction of Qualcomm's valuable portfolio of tens of thousands of patents".
"The technologies invented by Qualcomm and others are what made it possible for Apple to enter the market and become so successful so quickly", Don Rosenberg, Qualcomm's general counsel, said in a statement. About 1.4 billion smartphones were sold past year, according to IDC.
While the agreement worked for several years, Qualcomm chose to stop paying Apple when it found that the company was making "false and misleading" statements to the Korean Fair Trade Commission, which was investigating Qualcomm at the time over antitrust violations. That dispute is focused on Qualcomm's patent royalties with Apple and involves billions, Cnet said. The chipmaker has said it ended the rebates because Apple instigated antitrust investigations of Qualcomm and lied to regulators. Apple wasn't so lucky in Germany, where a Munich court blocked the sales of certain older iPhones that use chips from Intel. Apple has sought to dismantle what it calls Qualcomm's illegal business model of both licensing patents and selling chips to phone makers.
In yet another dispute, the Federal Trade Commission accused Qualcomm of monopolist business practices, the initial volley in a web of litigation that now spans 3 continents. That case, which is going to trial in Qualcomm's backyard of San Diego, will have a judge deciding it Apple must hand over royalty payments to Qualcomm for its iPhones. The trial concluded in January and parties are awaiting a decision.