DALLAS, TX.- Look, up in the sky! It's a bird! It's a plane! It's the most valuable comic book in the world.

A copy of Action Comics No. 1, the comic book that introduced Superman to the world in 1938, sold for $6 million Thursday at Heritage Auctions during the first session of the latest four-day Comics & Comic Art Signature® Auction. Graded CGC Very Fine+ 8.5, this issue from the Kansas City Pedigree is one of the world's finest copies. Only two other unrestored issues featuring Superman's first flight – or, at least, his first leap over a tall building – have ever graded higher.

Superman leaps over the world record previously held by … Superman. According to CGC's list of the most expensive comic books ever reported sold, a copy of Superman No. 1 sold privately for $5.3 million in 2022. The previous auction record was held by the CGC Near Mint+ 9.6 copy of Amazing Fantasy No. 15, featuring the debut of Spider-Man, that sold for $3.6 million at Heritage in September 2021.

There are just 78 copies of Action Comics No. 1 in CGC's population report, with the grading service estimating there are a scant 100 survivors of the comic book that launched superheroes into popular culture — 100 out of the 200,000 copies printed by DC Comics' predecessor National Allied Publications. Little wonder copies are so coveted by collectors when they appear at auction. Look no further than Heritage's September 2023 sale of an issue graded CGC 0.5 for $408,000, which leaped over the previous record in a single bound.

Action Comics No. 1 is hailed as the most important comic ever published, and the Superman who first appeared in the spring of 1938 remains remarkably like the version still filling comic-shop shelves every week or awaiting yet another big-screen turn in writer-director James Gunn's retelling of the tale. He was more violent than the Big Blue Boy Scout of the 1950s and '60s, but that's only because his creators wanted him to be "very serious about helping people in trouble and distress," Jerry Siegel once said. And in the case of Action Comics No. 1, trouble and distress were not in short supply: In his debut alone, Superman squared off against "unjust imprisonment, spousal abuse, disarmament and drunken driving," as Les Daniels summed it up in Superman: The Complete History.

Thursday was a Super-day on several fronts, as Siegel's historic 1934 letter to comic strip artist Russell Keaton describing The Man of Steel who could have been (a time traveler from Earth's far-flung future!) realized $264,000 to open the four-day Comics & Comic Art event. That letter hailed from the collection of publisher and artist Denis Kitchen, namesake of Kitchen Sink Press, whose collection of some 275 works of original art serves as another of this auction's highlight offerings.

And moments after the record-setting Action Comics No. 1 took flight, it was followed by what could have been the centerpiece of any other auction: a professionally restored copy of Action Comics No. 1 bearing the CGC grade of Apparent 8.0, which realized $576,000 – an all-time high for any restored comic book."The first three lots today would be tough to beat when it comes to exciting bidding wars – the all-time record for a comic book, bracketed by two absolutely stunning surprises," says Heritage Auctions Vice President Barry Sandoval. "We're thrilled to have made history today with an auction that's rich in history, encompassing everything from a pre-Golden Age Superman artifact to the Teenage Mutant Ninja Turtles. We couldn't be happier for our consignors and those winning bidders who acquired items without equal."

Superman was far from the lone record-setter during the first day of the April 4-7 event.

One of the five best copies of 1963's The Avengers – featuring Thor, Iron Man, Hulk, Ant-Man and Wasp – sparked a bidding war during Thursday's first session. And in the end, this CGC Near Mint+ copy of the book written by Stan Lee and drawn by Jack Kirby realized $432,000, a new record for the beloved title.

Speaking of super copies of books featuring super teams: There are two copies of Justice League of America No. 1 graded CGC Near Mint+ 9.6 – and none higher. That's why this stunning copy of the Super Friends' first outing in their own title realized a record-setting $348,000.

The CGC Near Mint+ 9.6 copy of the comic book that featured Wonder Woman's second appearance is a sensation in every regard. Not only is this copy of Sensation Comics No. 1 exquisite and historic, but it's also the highest-graded copy in the world. On Thursday, it realized a record-setting $420,000.

Daredevil, who's about to be Born Again in a new Disney+ series, was another record-setting star in this event, as The Man Without Fear's debut in Daredevil No. 1 realized $360,000 with a CGC Near Mint/Mint 9.8 copy.

And Doctor Strange's debut in Strange Tales No. 110 realized a record-setting $150,000, which proved that beauty is in the Eye of Agamotto, as this CGC Near Mint+ 9.6 copy is one of the five highest-graded in the world.