Shoppers wait in line to pay for their p

Walmart's stock has fallen since it reported disappointing earnings.

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Walmart shares have lost more than $30 billion in the last two days as the heirs of the family that founded the company lost more than $30 billion.

The reason for the carnage? The company said on Tuesday that its profits had been slammed by higher costs. Net income fell 25% from a year ago, with earnings per share coming in below analyst estimates.

The worst single-day decline for the company since 1987 was caused by investors. The wipeout didn't end there, with shares falling on Wednesday. The S&P 500 lost 4% on Wednesday, but the market was down broadly.

Walmart CEO Doug McMillon said on the company's earnings call that the first-quarter performance was disappointing, but that they would put it behind them and have a strong year.

The children of founder Sam Walton saw their fortunes wiped out in the last two days. The fortune of their sister-in-law was contracted by more than $1 billion. Lukas saw his net work knocked down by over $2 billion after he received a larger share of his father's estate.

Both Ann and Nancy lost over $1 billion when they took over the company from their father.

As of late Wednesday, Forbes estimates that the Waltons have a cumulative fortune of $212 billion. Jim is the 19th richest person in the world with a net worth of $59 billion, followed by sister Alice and brother Rob.