Commission-free trading app Robinhood responded to comments made by billionaire investing legends Warren Buffett and Charlie Munger on Saturday, claiming the pair "insulted a new generation" of investors for "doing things in a new way."

"If the last year has taught us anything, it is that people are tired of the Warren Buffetts and Charlie Mungers of the world acting like they are the only oracles of investing. And at Robinhood, we’re not going to sit back while they disparage everyday people for taking control of their financial lives," Jacqueline Oritz Ramsay, head of public policy communications at Robinhood, wrote in a blog post on Monday.

Ramsay added that Robinhood is "proud" for making "investing simpler and more accessible to more people."

The communications exec asserted that Robinhood and other no-fee platforms "have opened the doors of financial markets to everyday people, deeply unsettling the old guard who will fight to keep things the same." She went on to tout the app's fractional share ownership offering.

"At Robinhood, people now don’t need thousands of dollars to begin investing. We pioneered commission-free trading, and fractional shares make it possible for people with less money to invest in a piece of a stock. Take Berkshire Hathaway Class A stock. One share trades for north of $400,000. But with Robinhood, fans of the company can invest what they can afford and don’t need to amass what is a prohibitive sum for most Americans. Plenty of Robinhood customers do just that by buying a fraction of Berkshire Hathaway stocks, as well as many other stocks that Messrs. Buffett and Munger have invested in. In fact, we see that a majority of Robinhood’s customers are buying and holding," she wrote.

At Berkshire Hathaway's (BRK-B, BRK-A) annual meeting on Saturday, Buffett said he’s "looking forward" to reading Robinhood’s S-1 as he proceeded to subtly criticize the no-fee brokerage app, while his long-time partner, Munger, outright lambasted it.

Speaking at the conglomerate's annual shareholder meeting, streamed exclusively on Yahoo Finance, Buffett said Robinhood has "become a very significant part of the casino aspect of the casino group that has joined into the stock market in the last year or year and a half."

A wave of new investors has flooded the stock market, with lockdowns, no-fee trading, and stimulus checks making it easier to open up a brokerage account and start trading. Robinhood points out that "retail investing in America is thriving today because everyday investors are seizing the opportunity to build their own nest egg." Robinhood also noted that "technology is the great equalizer. And when it comes to investing, equal opportunity and accessibility is exactly what Robinhood is built to provide."

With free trading, Buffett said it "would be interesting to watch" how Robinhood describes its source of income in the S-1. He pointed out that Robinhood's commission-free trading has resulted in a surge in put and call options trading that's "gambling on the price of Apple."

"There's nothing illegal about it. There's nothing immoral, but I don't think you'd build a society around people doing it," Buffett added.

He continued: "If a group of us landed on a desert island knew we would never be rescued and I was one of the group and said, 'I'll set up an exchange over here and I'll trade our corn futures and everything around it,' I think the degree to which a very rich society can reward people who know how to take advantage, essentially, of the gambling instincts of not only the American public, the worldwide public, it's not the most admirable part of the accomplishment."

While reiterating his thesis that American corporations are a "wonderful place for people to put their money and save," he added that "they also make terrific gambling chips."

"And if you cater to those gambling chips when people have money in their pocket for the first time and you tell them make 30 or 40 or 50 trades a day and you're not charging commission but you're selling their order flow or whatever — I hope we don't have more of it. And I will be interested in reading the prospectus."

Meanwhile, Munger, took a much stronger stance against Robinhood, calling it "God awful that something like that would draw investment from civilized men and decent citizens."

"It's deeply wrong. We don't want to make our money selling things that are bad for people," Munger continued.

Buffett chimed in, bringing up the lotteries put on by states.

"I know, but that's bad, too," Munger said. "That's very bad. That's one of the things that's wrong with it — it's getting respectable people to do these things. The states are just as bad as Robinhood."

Buffett added that the states "in a sense are worse" because they're "taxing hope."

It's not the first time Munger has criticized Robinhood. At the Daily Journal annual meeting, a legal software and publishing company where Munger is also chairman, the 97-year-old called the no-fee business model “a dirty way to make money.”

Julia La Roche is a correspondent for Yahoo Finance. Follow her on Twitter.

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