Comic Book Addicts The James Gunn Effect: How the DCU Ignites Back-Issue Speculation The James Gunn Effect: How the DCU is Igniting the Comic Book Back-Issue Market For decades, comic book speculation followed a predictable script: a movie trailer drops, an actor is cast, and a character’s first appearance jumps in value overnight. … The James Gunn Effect: How the DCU Ignites Back-Issue Speculation Comic Books