The WallStreet.com Web address failed to sell at a Florida auction last week after bids fell short of the owners' $5 million reserve price.
The highest bid for the domain was a reported $3 million - below the $4 million to $5 million the owners wanted - at the auction managed by Moniker.com.
WallStreet.com had been tipped to challenge Porn.com, which sold for $9.5 million in May, for the title of most expensive domain name of the year.
The Web address has been idle since a European Internet entrepreneur and two other investors bought it from a Caribbean-based casino for $2.3 million four years ago. The owners are reportedly now seeking higher bids through a Web-based auction.
Computer.com sold for $2.2 million in last week's auction, while Investment.com fetched $900,000.
Sex.com is believed to be the most expensive domain name ever sold - it went for a reported $12 million in a private sale in January 2005, whilst Vodka.com sold for about $3 million earlier this year.