Netflix (NFLX -0.62%) subtly suggested that the leading video service's stock had gotten ahead of itself, and billionaire trader Carl Icahn took note. Shares of Netflix moved lower after an SEC filing showed that Icahn had trimmed his stake from 9.4% to 4.5%. Icahn, and his affiliated parties, had actually started to trim their stakes earlier this month, but the lion's share of the stock being sold was unloaded yesterday at $341.44 a share.

That's certainly not too shabby for a guy who had bought in back when Netflix was in the double digits, nearly a year earlier. He may be unloading more than half of his original stake, but it's important to note that he has nearly twice as much money riding on Netflix now, at 4.5% of the company, than he did late last year, with 9.4%. That's what happens when you have a stock more than quadruple, and you take some money off the table.

Icahn made out far better this time than he did several years ago when he figured that Netflix rival Blockbuster -- now owned by DISH Network (DISH) -- was the smarter activist play. 

After DISH Network picked up the remains of the once-dominant video rental chain, Icahn wrote in a Harvard Business Review article in 2011:

Blockbuster turned out to be the worst investment I ever made. It failed because of too much debt and changes in the industry. It had too many stores, Netflix created a better business model, and then Redbox kiosks and the whole digital phenomenon eliminated the need for consumers to go to a separate DVD store.

He got his wish a year later when he was able to buy into Netflix at a cost basis of just $58 a share.

Icahn even tweeted his partial exit, thanking Hastings, content chief Ted Sarandos, and even House of Cards star Kevin Spacey.

Where does this leave investors? 

Well, they may feel like blaming Hastings for being so darn honest about the volatile nature of his stock. He pointed to the stock's torrid run in 2003 -- similar to this year's surge -- before shedding more than half of its value a year later. Hastings argued that Netflix's growth has been reasonably steady, leaving the spikes and lulls of investor confidence to drive the stock higher and lower.

Icahn had said nothing but positive things about Netflix in the days leading up to yesterday's large sale, but some pros were starting to get worried. 

RBC Capital Markets analyst Mark Mahaney was discussing the possibility of an Icahn sale just last week on CNBC. His educated guess was that the stock would lose between 5% and 7% of its value on the news, but that was based on its price level at the time and, likely, Icahn moving to unload his entire position.

It's easy to preach about letting your winners run, but Icahn is a trader. He made enough money here to make several similar-sized bets in the future. Maybe Hastings knew that this would happen. Maybe this is why Hastings was so critical about the stock's rally in Monday night's letter to shareholders.