Watch out for falling fortunes.

The four members of the Walton family controlling more than half the shares of Wal-Mart Stores Inc. had $11 billion of their combined net worth evaporate Wednesday as shares of the retailer plunged on a lower earnings outlook for the coming fiscal year.

The billionaire Waltons -- Christy, Jim, Alice and Rob-- have a combined $120 billion fortune, according to the Bloomberg Billionaires Index, with the bulk of their wealth in the shares they inherited from Wal-Mart founder Sam Walton. The four shareholders, three children of Sam and Christy, the surviving spouse of a fourth sibling, are among the year’s worst- performing billionaires, losing a total of $41 billion since Jan. 1.

The Bentonville, Arkansas-based mass merchandiser, which once famously promoted its discount strategy with the phrase "Watch out for falling prices," announced earlier Wednesday that earnings will slip as much as 12 percent in fiscal 2017, which ends in January that year. Analysts had been estimating a slight gain. Wal-Mart shares fell 10 percent in Wednesday trading and reached their lowest level since May 2012, according to data compiled by Bloomberg.

The family members had a combined net worth of $169 billion in January when Wal-Mart reached a 2015 high of $90.47. They aren’t the only members of the index to suffer large losses this year. Mexican telecom tycoon Carlos Slim has the largest individual loss with $12.5 billion, followed by Warren Buffett, whose Berkshire Hathaway Inc. is a Wal-Mart investor, at $12.1 billion.