Two years ago, another copy of the 1938 Action Comics No. 1 sold for more than $2 million. This one, found by a Minnesota man in the wall of a house he was rebuilding, started off in less than mint condition and suffered further damage when the back cover was ripped off in an argument shortly after its discovery.
The renewed focus on Superman in the run-up to his movie reboot surely played a role in driving up the bidding price, as did the media attention surrounding its unusual provenance. But of course, what really made it so valuable is its utter rarity, with less than a hundred original copies estimated to still exist. So it's unlikely that you'll be finding a copy in your grandma's attic or hidden in a wall (or, for that matter, in a cornfield in Kansas).
Still, it's not too late to start collecting comics in the hopes of early returns. If you're looking for future comic book series that could be excellent investments, Tim Beyers of the Motley Fool passes along these tips from Jay Katz of InvestComics for building a profitable comic portfolio:
Buy quality. On rare occasions, you'll find a screaming deal in a bargain box or at a garage sale. More often, the best bets are made on high-quality comics that are valuable because they're tied to something in the broader culture (e.g., "The Walking Dead") or because they introduce a new character or signify some other major change.
Buy rarity. Sometimes, special events are so well-advertised that everyone buys the same comic book. I can think of no better example than "Superman" No. 75 from 1992, in which the titular character dies. A special bagged edition is guide-valued at $20, but you'll find plenty of copies on eBay selling for far less. Why? Millions are still available. By contrast, when "The Walking Dead" first hit comic book shops in October 2003, you had to be one of the lucky 7,000 to buy a copy.
Don't be afraid to sell. Comics get hot just like stocks. Assess whether the spike is due to an unsubstantiated rumor (e.g., someone's cousin showed this comic to a studio executive!) or a new character or major event that's suddenly taken on wider meaning. Hold only the comics likely to maintain or grow their value, and harvest the rest to raise cash for new buys. How can you tell when a comic book has intrinsic value? Take "Iron Man" No. 55 as an example, which introduces the cosmic villain Thanos. The 1973 comic sells for $1,000 now that Marvel has established Thanos as a big-screen adversary who could next appear in 2014's "Guardians of the Galaxy."
Which new series are most likely to bring enterprising investors these sorts of riches? Here are five worth checking out.