Source: World Wresting Entertainment.

We should never blindly copy any investor's moves, no matter how famous, talented, or successful the investor. Still, it can be useful to keep an eye on what smart folks are doing. 13F forms can be great places to find intriguing candidates for our portfolios.

For example, a glance at the latest quarterly 13F filing of Citadel Advisors shows that it closed out its position in World Wrestling Entertainment (NYSE:WWE), selling some 772,000 shares that would be worth more than $11 million today.

Why pay attention to Citadel Advisors?
Founded and managed by Kenneth Griffin, Citadel Advisors is one of the biggest hedge fund companies around, with a reportable stock portfolio totaling $74 billion in value as of June 30. According to the folks at InsiderMonkey, Griffin and his team use "a combination of advanced computer code, complicated financial algorithms and secrecy. Griffin was using quantitative, technology-based methods before many other firms had cell phones."

Why sell World Wrestling Entertainment?
Why would the folks at Citadel, not to mention any other investor, sell World Wrestling Entertainment? Let's review a few reasons, starting with the dividend. Yes, it yields an appealing 3.6%, but the payout is $0.48 per share annually --  more than the company's earnings per share in 2011, 2012, and 2013 -- and its trailing 12-month earnings are in the red. The dividend is also a third of what it was in 2011, reminding us that these payouts do get reduced or eliminated.

Then there's World Wrestling Entertainment's business itself. These are days of rapid changes in how entertainment is delivered. Many people are dropping cable and relying on streaming services, for example. World Wrestling's pay-per-view service was struggling, so the company developed its own streaming service, a network it could sell directly to consumers, bypassing the cable middlemen and asking for $10 per month for access to all its programming. That wasn't such a crazy idea, but things have not worked out well for the company lately: After claiming 667,287 subscribers in its first 42 days, the service only netted about 33,000 more in the following three months, which ended July 31. Even worse, the churn rate was terrible, with many subscribers going out of their way to cancel.

The company's valuation is also a concern, with its recent P/E ratio suffering from net losses, its forward P/E near 23, and its price-to-sales ratio of 2.1 slightly above its five-year average of an even two. Believers see this as an attractive entry point, but the stock doesn't seem to be at screaming-bargain level yet.

World Wrestling Entertainment has addressed some of its problems by slashing its workforce by about 7%. That can be good if a company is trimming fat, but this is being done in a more desperate environment, and at those times, muscle and bone can get cut, reducing performance potential.

Why buy World Wrestling Entertainment?
It's hard to come up with many reasons to invest in this company, given the rough patch it's going through now. It does have great international expansion plans, which could serve it well -- but many international viewers will be expected to watch programming in a language they don't understand.

It has a strong brand and many loyal fans and potential customers, too. With its business model, WWE's profitability can increase substantially if it can bring in more subscribers and boost retention of those viewers. Some see its goal of 1.3 million subscribers (or more) by the end of this year as achievable, and they like its licensing agreements, too, for its show Raw on the USA Network and SmackDown on SyFy. Bulls note that streaming-video company Netflix started small as well.

The 3.6% dividend yield is attractive, but the company has reduced its payout before and may well do so again.

The bottom line here is that you can find great potential and far less risk in other stocks. If you own shares, you might want to join Citadel Advisors and sell -- or at least watch carefully for signs of further deterioration (or success, which is possible). With some more promising numbers for its streaming service, this company will look a lot more attractive.