A 17-year-old boy remains in hospital in a serious, but stable condition after being found with stab wounds on Friday night on Wood Street, Edgeley.
No arrests have been made and enquiries are ongoing.
Detective Inspector Charlotte Whalley, of the Stockport Division said: “This was a mindless attack that has left a young boy in hospital with serious injuries.
“I would like to reassure the community that this is being treated as an isolated incident, and there is not believed to be any threat to the wider public.”
“We are particularly keen to speak to anyone that was on or around Wood Street at the time of the attack. If you have any information, please contact police as soon as possible.”