Walmart founder Sam Walton's son follows Warren Buffett's lead and unloads shares as Amazon takes over

Rob Walton has sold shares from his family company.

Walton, who is the son of founder Sam Walton and served as chairman of Walmart until 2015, has unloaded shares of the retailer totaling $62.3 million, according to SEC filings reviewed by CNBC.

Walton sold a total of 775,958 shares in two separate transactions on August 23 and 24. He still owns 106.3 million shares worth more than $8.4 billion.

Walton is also still a member of the Walmart board. Since he sold less than 1% of the Walmart stock he owns, it's difficult to speculate what the reason for the sale might be.

Walmart slightly outperformed the S&P 500 index so far this year, up roughly 10.5%. Analysts are split on Walmart, according to CNBC: 14 have buy, 15 hold and, two advise to sell the stock.

Investors fears are growing, however, as Amazon squeezes the retail market and pushes into more of Walmart's core businesses, like organic grocery. Walmart is currently the largest seller of organic food in the US, but it now has stiff competition as Amazon recently sharply cut prices at its new acquisition, Whole Foods.

Another high profile investor recently sold Walmart shares: Warren Buffett. In February, the legendary investor dumped almost all of his Walmart stock in a high publicized sale that underlined the trouble retail finds itself in as of late.

A Walmart spokesperson has did not immediately respond to request for comment.