Elon Musk speaks onstage at Elon Musk Answers Your Questions! during SXSW at ACL Live on March 11, 2018 in Austin, Texas.

Billionaires Elon Musk and Warren Buffett engaged in a war of words over the weekend.

In an earnings call last week, Tesla co-founder Musk criticized so-called "moats" but he wasn't referring to the sort of moat you'd find around a castle. Instead, he was talking about the term coined by Buffett, referring to a buffer that companies need surrounding them to help them maintain a competitive edge. According to Musk, "the pace of innovation" is more important.

But Buffett shot back on Saturday, arguing that companies with strong, sustainable moats do exist and that technology has not destroyed them in every industry. The billionaire investor and CEO of Berkshire Hathaway quipped: "Elon may turn things upside down in some areas. I don't think he'd want to take us on in candy." Berkshire Hathaway owns See's Candies.

Following Buffett's comments, Musk said on Twitter that he was "super super serious" about starting his own candy company.

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Berkshire Hathaway bought See's Candies in 1972 and is still the confectioner's parent company to this day.