Zero-day markets are channels (legal and gray/black) where discovered vulnerabilities are bought and sold — nation-state intelligence agencies, defense contractors, and cybercriminals pay millions for reliable exploits.
Zero-day prices: iOS full-chain remote jailbreak = $2-5 million. Chrome renderer RCE = $500K. Organizations can reduce zero-day risk through defense in depth, behavioral detection, and attack surface reduction — no patch = focus on detection.