The rare issue—published in 1939 and originally priced at just 10 cents—is considered one of the most coveted comic books ever printed. Its exceptional condition, combined with the fact that it comes from the original 500,000-copy print run, sent its value soaring to historic levels.

The story behind the discovery is just as remarkable. One year ago, three siblings uncovered the comic tucked away in a cardboard box in the attic of their California home while sorting through their late mother’s belongings. She had often mentioned owning a valuable comic collection, but none of them imagined she had a treasure of this magnitude hidden above their heads.

Until now, the record had been held by the first issue of Action Comics, which sold for €6 million. With this sale, Superman has officially leapt to the top of the comic-book-collecting world—faster, as the saying goes, than a speeding bullet.