If there were a hedge fund manager hall of fame, Ken Griffin would be a no-brainer inductee. His skillful leadership of Citadel made it one of the most successful hedge funds ever. It also made Griffin one of the wealthiest people in the world, with a net worth of nearly $37 billion.

Understandably, many investors pay close attention to the stocks Griffin buys and sells. Are income investors in this group? There's a good argument that they should be. The billionaire just loaded up on one high-yield dividend stock.

4x for Pfizer

Griffin isn't known as a buy-and-hold investor because his Citadel hedge fund often owns stocks for short periods. However, big drugmaker Pfizer (PFE 0.98%) is an exception.

Citadel first initiated a position in Pfizer in the second quarter of 2013. Its portfolio has included the pharma stock since then, albeit with quite a few major increases and decreases in the number of shares owned along the way.

We just saw one of those big swings in the fourth quarter of 2023. Griffin increased Citadel's stake in Pfizer by more than 4x, purchasing 9.34 million shares. The hedge fund's position in the company was worth $334.8 million at the end of Q4.

This sizable increase follows a series of big purchases of Pfizer stock by Citadel. Griffin also bought shares of the drugmaker in the first three quarters of 2023.

Why does Griffin like Pfizer?

As far as I know, Griffin hasn't commented on Citadel's aggressive buying of Pfizer. However, we can make some pretty good guesses about why he likes the stock.

For one thing, Pfizer is valued attractively. The stock trades at less than 12.2x forward earnings after plunging 35% over the last 12 months and 55% since early 2022. By comparison, the S&P 500's forward earnings multiple is nearly 20.9.

Another benefit of Pfizer's steep decline in share price is that its dividend yield now stands at 6.3%. This yield is near the highest level in more than a decade. Griffin knows Pfizer's share price doesn't have to increase much for the stock to deliver market-beating total returns with such a juicy dividend yield.

Griffin also realizes investing is similar to chess: You should look multiple moves ahead to be successful. Pfizer's current status seems bleak. Sales for its COVID-19 products continue to tank, and the company faces patent expirations for several blockbuster drugs over the next few years. However, Pfizer's prospects should improve considerably in the future.

The big pharma company expects the launches of new products and new indications for existing products initiated by mid-2024 will generate an additional $20 billion in annual revenue by 2030. This amount more than offsets the projected negative impact of patent expirations. Pfizer also predicts business-development deals will contribute another $25 billion of annual revenue by 2030.

Should you buy this high-yield dividend stock too?

Is Pfizer a great pick for investors who aren't billionaire hedge fund managers? I think the answer is "yes" -- at least for some.

Growth investors might not find Pfizer all that appealing. Even with new product launches and business development deals, the drugmaker's growth prospects won't be as strong as many other stocks on the market.

On the other hand, Pfizer could be an ideal candidate for income and value investors. There's no question that the stock offers a fantastic dividend and a relatively low valuation. I suspect Pfizer will deliver solid total returns for patient investors.