Story highlights 1938 comic book marks the first appearance of Superman

It's considered a gem among comic book fans

(CNN) A rare copy of a Superman comic book sold for nearly $1 million this week.

The 1938 comic book marks the first appearance of Superman, and is considered a gem among comic book fans, according to Heritage Auctions . It was expected to sell for $750,000 but fetched $956,000.

The rare copy of a comic book was expected to sell for $750,000, but sold for $956,000 instead.

About 100 copies of the comic book are believed to exist decades after production.

"Few copies of this comic survive, let alone come to auction with such a bright cover," said Lon Allen, managing director of comics and comic art at Heritage Auctions

The comic book sold Thursday was part of a collection owned by a fan who bought it in the 1990s for $26,000, Dallas-based Heritage Auctions said.

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