The former pick 8 had a terrific debut season but has struggled with injury this year recently suffering a "Lisfranc injury that will see him miss an undefined period."
Cox said he was happy to commit to what the Bombers are trying to build along with his fellow 2020 draftees.
"I'm so happy to have signed with the club for a further two years, especially with the likes of Archie and Zach also committing to the club,” Cox said in a statement.
“We have a great core group of young players who have a lot of development ahead of us, but we are building something special and I can’t wait to be a part of it.”
General manager of list and recruiting Adrian Dodoro said the club was happy with the development of the 202cm Cox in the early stages of his career.
“Nik is a wonderful signing for the club. He has really impressed us with his development over his first two years, especially last year where he only missed one game,” Dodoro said.
“He has so much potential and can play a variety of roles so I look forward to seeing Nik continue to grow his game over the next couple of years.”
Perkins also signed a two-year deal while Reid committed until the end of 2025.
The Bombers have been on a signing spree in recent weeks with Kyle Langford and Sam Durham both putting pen-to-paper in recent weeks but there are still some high-profile names without a deal to their name.
Andrew McGrath and Dyson Heppell are both yet to have their futures locked away with the former reportedly gaining interest from Richmond and St Kilda. McGrath is seen as a potential captain within the four walls at the Hangar once Heppell's time in the role is up.
Heppell is yet to be offered a deal from the Bombers with the soon to be 30-year-old keen to go on. Being deployed off halfback under Brett Rutten, Heppell's role within the side has been under question from some recently.
"Let's start with the captain – is he in their best half-back group? Does he have a role in the team at the moment?" David King asked on SEN's Whateley just over a fortnight ago.
"It's difficult when your captain's not in great form. Where does he sit in terms of the half-back flankers in the competition right now? Would you have him in the top 10 half-back flankers? Definitely not. Would you have him in the top 20? Probably not.
"He's not damaging by foot, he can't stop a man, he's getting his positioning wrong regularly and being made to look second rate because the ball movement's coming so fast and the midfield's not putting any pressure on. Everything's working against him."