Investors pulled $2.4 billion from four major mutual funds managed by Guggenheim Partners in September, following reports that U.S. regulators are investigating the business dealings of the firm's Chief Executive Officer, Mark Walter.

According to Morningstar estimates, $1.8 billion of that total flowed out of the Guggenheim Total Return Bond Fund, the company's largest publicly traded mutual fund. The outflows represented 6.1% of the fund's managed assets, which declined to less than $29 billion.

Morningstar data shows that the Guggenheim Macro Opportunities Fund saw investors redeem $222.4 million, while the Guggenheim Limited Duration Fund experienced outflows of $317 million and the Guggenheim Core Bond Fund lost $64.9 million.

The redemption volume across Guggenheim's mutual funds in September rose sharply compared with $647 million in August and $103 million in July.

A Guggenheim spokesperson stated, "Our funds continue to deliver competitive investment performance, with each of the aforementioned funds holding a four- or five-star rating from Morningstar. We are working closely with our clients, monitoring their portfolios, and managing risk in the current market environment."

Federal prosecutors and the U.S. Securities and Exchange Commission have been investigating potential misconduct at Walter's insurance companies as well as at Guggenheim. The investigation focuses on how the billionaire, who owns the Los Angeles Dodgers, was able to borrow from these insurance companies without the companies disclosing those loans to state regulators as required.