In case you missed it, institutional funds recently disclosed their latest equity holdings for the third quarter of the year in their 13F forms filed with the Securities and Exchange Commission (SEC).

The SEC requires funds managing more than $100 million in assets to file these forms within 45 business days after the close of each quarter. 13Fs can be useful for retail investors because institutional fund managers are professionals who often have decades of experience, more resources, and a strong understanding of what makes a stock work.

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While investors should certainly keep up with fund managers, they should not follow them reflexively into investments. Professional investors often invest larger sums of money seeking returns over shorter time horizons than retail investors. Additionally, some of these funds are huge so you don't know exactly who is pulling the buy or sell button. And then, of course, even the best are sometimes wrong, so make sure to do your due diligence.

That said, following fund managers can be a great way to find new investment ideas and check your thesis on existing positions in your portfolio. In recent months, several funds run by billionaire investors have piled into a stock-split company trading on the Nasdaq stock exchange that has struggled this year but pays a healthy dividend. Could they be onto something? Let's take a look.

A big corporate change

The market has been on a two-year bull run, and the S&P 500 index seemingly hits new highs every day and is up close to 27% this year, so most stocks have done well. However, digital audio leader Sirius XM Holdings (NASDAQ: SIRI) is down more than 52% this year. Sirius has been on quite a ride, and investors have seemingly left the stock for dead, hitting lows not seen in five years.

While the market seems to have forgotten about it, several prominent billionaires are piling in. Warren Buffett's company Berkshire Hathaway has been buying shares all year. Buffett now holds a more than $2.9 billion stake in Sirius, which makes up 1% of Berkshire's roughly $300 billion portfolio.

In the third quarter, Ken Griffin's Citadel Advisors took a new position in the common shares, valued at more than $59 million. Griffin held calls and put positions in the second quarter.

Sirius has struggled in recent years as debt has piled up and paid subscribers have declined. However, the company recently split off from Liberty Media and conducted a reverse 1-for-10 stock split. The moves were designed to increase the stock price and simplify the corporate structure, both of which can help attract more institutional interest.