Reuters reported Judge Reggie Walton said he could not conclude the SEC made a "good faith effort" to search for records that Cuban had requested under the federal Freedom of Information Act.
Judge Walton scheduled an Oct. 22 hearing to set a timetable to release the documents.
"We would describe the ruling as a complete victory," said Lyle Roberts, a partner at Dewey & LeBoeuf LLP representing Cuban. "The judge was sharply critical of the SEC's efforts."
On Tuesday an appeals court reinstated the lawsuit against Cuban. The Dallas resident is accused of selling shares of stock in the company Mamma.com after getting inside information about the company's plans.