Privately, Warren Buffett bought and sold stocks for Berkshire Hathaway. PublicAction

 Privately, Warren Buffett bought and sold stocks for Berkshire Hathaway. PublicAction

Due to his declaration that doing so would create a conflict of interest, Warren Buffett steers clear of these stocks.

In a 2012 interview, Buffett said that since Berkshire did not own a single share in JPMorgan Chase, he had invested in the bank even though he favored Wells Fargo.

According to a Pro Publica research, renowned investor Warren Buffett has, at least three times, exchanged equities in his personal account in the same quarterly or a quarter before Berkshire Hathaway acquired or sold the same companies. Buffett leads Berkshire Hathway as both its chairman and CEO.

Investigative journalism is the focus of Pro Publica, a nonprofit organization with headquarters in New York.

Buffett's trading information were allegedly discovered in Internal Revenue Service (IRS) data leaks, according to ProPublica.

Buffett avoids purchasing what Berkshire was buying because he has always said that doing so would create a conflict of interest.

The case study of Wells Fargo opens the investigation report. According to the article, Buffett gave the bank high marks, noting that it had "come closer than any other big bank by some margin" to an efficient business model. According to the article, this was said in an interview conducted on April 20, 2009, when the financial crisis was still looming large over the institutions. According to Pro Publica, the bank's shares had increased by 13% in only four days by April 24.

It said, "On that day, Buffett sold off shares of Wells Fargo approximately $20 million in private in his personal account."

Buffett said in a 2012 interview that he had made an investment in JP Morgan Chase because Berkshire did not have any shares in the company.

He continued by saying he would have chosen Wells Fargo but could not because Berkshire owned its shares.

He said, "That's one of the problems I have," according to a transcript from ProPublica from the interview. Since I have some money and I can't afford what Berkshire is purchasing, I turn to my backup options or small little businesses.

According to ProPublica, David Sokol of Berkshire had to step down in 2011 when it was discovered that he had purchased stock in a chemical firm that Berkshire had shortly after bought.

Buffett was cited at this time as claiming that regulations weren't the issue. He said, "People breaking the rules is the problem."

Buffett did, however, sell $35 million worth of Johnson & Johnson shares in October of the following year, 2012. By the end of that quarter, Berkshire had also sold those identical shares. According to the study, Berkshire sold millions more shares over the course of the next two quarters.

According to Berkshire's policy, employees should not trade in the investee business's shares "prior to the public disclosure by Berkshire of its actions" if they become aware that the corporation has taken or changed its position in the investee company.