The official statement from Netflix:
"Marvel’s Daredevil will not return for a fourth season on Netflix. We are tremendously proud of the show’s last and final season and although it’s painful for the fans, we feel it best to close this chapter on a high note. We’re thankful to our partners at Marvel, showrunner Erik Oleson, the show’s writers, stellar crew and incredible cast including Charlie Cox as Daredevil himself, and we’re grateful to the fans who have supported the show over the years. While the series on Netflix has ended, the three existing seasons will remain on the service for years to come, while the Daredevil character will live on in future projects for Marvel."