After Walmart cut its earnings forecast, the Walton wealth fell about $19 billion.
Family-controlled Walmart slumped 11% in New York trade after reporting disappointing results.
Soaring inflation pressured the retailing giant's first-quarter profit margins, challenging its willingness to boost prices.
The late Sam Walton built the company on a cheap mentality that has helped it weather recessions in the past.
The family, which holds a holding via trusts, has increased stock sales recently.
Last year, they sold $6.2 billion in shares as part of a plan to maintain their ownership below 50% during buybacks.