Momentum has been the name of the game for traders this year. There are countless stocks that have risen manyfold since the beginning of 2013 and internet stocks have led the pack. This is why the king of floor traders, Art Cashin, said last week that the current environment feels a lot like the internet bubble to him.

But momentum is a fickle friend. Should the euphoria in these stocks begin to wane traders could jump ship just as quickly as they hopped on. Here are a few to pay attention to:

nflxNetflix announced earnings yesterday and CEO Reed Hastings had this to say:

In calendar year 2003 we were the highest performing stock on Nasdaq. We had solid results compounded by momentum-investor-fueled euphoria. Some of the euphoria today feels like 2003.

Props to Reed for having the balls to say what I’m sure plenty of other execs are thinking. After surging 10% on earnings Netflix has seen a pretty brutal reversal and is now down half as much as it gained earlier in the day.

fbFacebook has seen its stock price more than double over the past 3 months despite the fact that all reports suggest its flagship site is waning in popularity.

lnkdLinkedIn has been a favorite of internet investors for quite a while and for good reason; it’s probably got the most solid business plan. The stock price took a good hit a couple of weeks ago and though it has recovered nicely since it hasn’t been able to follow the indexes to new highs.pPandora has had a terrific year by any standard but looks to be forming a broadening top pattern.zZillow has now formed a clear head and shoulders top with implications for both the momo internet stocks and possibly the real estate sector.tslaTesla is perhaps the most beloved of all as it’s been the best performer of this group. Like Zillow, it has also formed a head and shoulders top pattern. Should investors lose faith here it could sour the mood toward momentum stocks in general.

UPDATE:

Add these two to the list, as well (HT, Toddo):

yelpYelp has tripled over the past few months.

pclnTraders like to say, ‘don’t short the Shat,’ but nothing goes up in a straight line forever – not even Priceline.com