A 1979 Wayne Gretzky rookie trading card sold for $474,687 at the National Sports Collectors Convention in Atlantic City on August 4.
The piece is in gem mint condition and last sold for a world record $94,162 at SCP Auctions in 2011.
That means it's achieved growth of 49% per annum over the last four years, a truly extraordinary rate of return.
Ken Goldin of Goldin Auctions, which hosted the sale, told ESPN that it indicated the "strength and diversity of the card market."
All are expected to realise sums well in the six figure range.
The sale also featured the Chicago Bulls jersey Michael Jordan wore in the 1998 Eastern Conference semi-final.
It sold for $168,000, making it the second most valuable Jordan jersey ever sold at auction.
The tournament marked Jordan's final appearance for the Bulls. Memorabilia associated with this time is in particularly high demand.
His record breaking jersey also dates to the 1998 season and realised $173,140.
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