“You’re under extraordinary pressures at a company that is growing that fast,” Mr. Fanlo said.

More than two dozen former SoFi employees said they were uncomfortable with Mr. Cagney’s pursuit of women in the office. In 2012, he sent the text messages to Ms. Munoz, the executive assistant, until her colleagues took the issue up with executives and the board, according to the five people who spoke with Ms. Munoz about the matter.

Even as Mr. Cagney was texting Ms. Munoz, he also chased another young female employee. Six employees said they saw Mr. Cagney and the employee holding hands and talking intimately. One day in 2013, when Mr. Cagney was flirting with her at the office in front of colleagues, she grew enraged and left, according to three employees who witnessed the episode. Soon after, she left the company.

Around that time, SoFi’s board asked Mr. Cagney to not engage in inappropriate conduct with employees, according to two people with knowledge of the conversations. The situations were awkward in the office given that Mr. Cagney’s wife, June Ou, began working at SoFi in 2012, rising to become the company’s chief technical officer. Her desk was near Mr. Cagney’s. Ms. Ou did not respond to a request for comment.

Pushing the Business

SoFi’s business works in the following way: It loans money to students, home buyers and individuals with high credit scores. The company funds those loans with money from hedge funds and banks, who buy the loans through securities or bonds that SoFi creates.

As early as 2012, Mr. Cagney ran into trouble with some of his investors. That year, the company said it had secured $90 million in debt financing for one of its loan products, called Refi A. But some investors who had bought the securities noticed their returns were not in keeping with SoFi’s estimates and voiced concerns to executives and to a board member, according to the emails obtained by The Times.

About 10 SoFi executives met to discuss the situation; it was then that some of them learned Mr. Cagney had not actually secured the $90 million for the loan product, according to people who were at the meeting. Some attendees said they were dismayed at the possibility that they had made material misstatements to investors.