By Angela Moon
NEW YORK (Reuters) - Popular stocks like Amazon, Facebook and Best Buy surprised investors with huge post-earnings swings this quarter - and some of them headed south fast - a big jolt for the market after 2013 saw many companies' shares rally with nary an interruption.
Investors have started to bet on big swings in other normally volatile stocks of companies due to report results in coming days, including Tesla Motors
But there is still a lot of room for shocks in the next few weeks. In many cases, the expectations for share volatility remains lower than the actual moves in such hot stocks in previous quarters.
"It's been a stellar couple of weeks for volatility players after a quiet 2013. The overall market has seen volatility grow substantially," said Randy Frederick, director of trading and derivatives at the Charles Schwab Center for Financial Research in Austin, Texas.
Even those that did well have surprised investors with the magnitude of the moves - Netflix rose 16.5 percent on January 23 after its results and Facebook Inc
Reflecting such caution, implied volatility for stocks of high-profile companies due to report in the next two weeks has risen in the last few days.
"We've been seeing a lot of movements this season and people might be on the edge and inclined to sell off more sharply. It's probably a wise idea to hedge a little more," said Rick Meckler, president of investment firm LibertyView Capital Management in Jersey City, New Jersey.
Expectations for Green Mountain Coffee Roasters is for a 15 percent move in shares post-earnings, but that's less than the average move of 25 percent in the past eight quarters, according to Goldman Sachs data.
The implied move on Tesla Motors
Other notable companies in the social media and Internet space, including Groupon, Expedia Inc
While some stock investors may be thrown for a loop, the larger-than-expected swings have been great for options traders who bet on volatility, no matter whether the stock goes up or down.
TWITTER'S FIRST EARNINGS DANCE
Social media play Twitter Inc
In its short life as a public company Twitter has already seen 17 trading sessions where it gained or lost more than 5 percent.
The expected post-earnings move is currently about $9.70, or about 14.5 percent up or down, an expectation that has been creeping up in the last two weeks.
"The fear of the unknown is particularly high for stocks of companies with no or a limited track record because you can't really draw a comparison to their peers or history. It's harder to have a view on how earnings will come out," said JJ Kinahan, chief strategist at TD Ameritrade.
Adding to volatility, short interest in Twitter surged to 33 million shares in January, more than 10 percent of the stock's available float.
Some bold bets were seen in the options market with traders buying and selling out-of-the-money strikes - options contracts with prices far away from the current price.
Top open interest positions in Twitter options ranged from $85 weekly strikes that expire on Friday, along with $47 out-of-the-money puts that expire on Feb 14. Even the most actively traded near-term strikes are well out of the money - February $75 and March $75 calls. The stock would need to rise about 13 percent from its close at $66.32 on Tuesday for those options to be profitable.
(Reporting By Angela Moon; Editing by Martin Howell and Grant McCool)