Comic featuring Superman's debut sells for record-breaking $6 million

April 5 (UPI) -- A copy of the comic book that introduced Superman to the world became the world's most expensive comic book when it fetched $6 million at auction.

Heritage Auctions said the copy of Action Comics No. 1, the 1938 comic book featuring the first appearance of Superman, attracted a record-breaking high bid of $6 million at Thursday's auction.

The comic book, featuring the iconic Man of Steel on its cover, was inspected by collectible-grading service CGC and given a grade of "Very Fine+ 8.5," making it the third-highest graded copy of Action Comics No. 1 known to still exist.

CGC said only about 100 copies of the comic are believed to still exist, as the service has only graded 78 copies over the years.

The comic was published by National Allied Publications, the predecessor to the modern-day DC Comics.

The previous record for most expensive comic book was a copy of Superman No. 1 that sold privately for $5.3 million in 2022.

The previous most expensive comic book sold at auction was a CGC Near Mint+ 9.6 copy of Amazing Fantasy No. 15, the first appearance of Spider-Man, which sold for $3.6 million in September 2021.