Thursday, during a Congressional hearing on the scandal, Rep. Carolyn Maloney (D-NY) accused Stumpf of using insider information about the phony accounts to cash in $13 million worth of his own shares before knowledge of the fraudulent activity at Wells Fargo (WFC) became public. Maloney said the timing of that trade raised questions of whether Stumpf put himself ahead of customers who had been defrauded, and ahead of the bank in general.

“The timing is very, very suspicious and it raises serious questions,” Maloney said.

Stumpf denied that he had done anything wrong. He said he sold stock with proper approvals and claimed the sales were made “with no view about what was going on.”

It was the first time that Stumpf’s own stock sales have become an issue in the phony account scandal. Last week, Sen. Elizabeth Warren (D-MA) claimed that Stumpf had personally made $200 million off the phony account fraud, which appears to have been tied to the bank’s aggressive cross-selling goals. But Warren didn’t allege any instance of insider trading, just that the value of Stumpf’s shares had risen during the time of the fraud.

According to Bloomberg data, Stumpf sold 300,000 shares of Wells Fargo stock on October 2013. Last week, in Senate hearing, Stumpf said that he first learned about the fraud in late 2013, but wasn’t clear about exactly when. He implied that he learned about it in the run up to the release of a Los Angeles Times article detailing the problems at Wells Fargo. The article, titled, “Wells Fargo’s pressure-cooker sales culture comes at a cost,” came out on December 21, 2013.

The article does not say how long the reporters were working on it, but does say it was based on 28 interviews and a through review of documents. One unnamed sales manager is quoted as saying, “It’s all manipulation. We are taught exactly how to sell multiple accounts. It sounds good, but in reality it doesn’t benefit most customers.”

Wells Fargo CFO Timothy Sloan is quoted in the story saying, “I’m not aware of any overbearing sales culture.”

It is impossible to know, from the outside, if Stumpf traded on insider information. Many CEOs and other executives use plans that automatically sell stock at regular intervals to avoid allegations of trading on insider information. Stumpf does not appear to have one of those plans set up. And he didn’t mention the existence of a blind plan on Thursday in his response to Rep. Maloney.

In fact, Stumpf doesn’t appear to have sold a single share of his stock holders for at least three years, before unloading the 300,000 shares in late October 2013. Stumpf on Thursday said the stock sale represented a small portion of his overall holdings, and that he holds four times as much stock in the company as he did then.

A filing from early 2013 showed that the stock sale represented about half of his total Wells Fargo stock holdings, but the executive did have options to buy as many as six million additional shares of the stock. A filing from earlier this year showed that Stumpf’s Wells Fargo stock holdings had risen to 1.6 million shares, but his overall holding in Wells Fargo, including stock and options had dropped to 5.4 million shares earlier this year from 6.6 million three years ago.