Doug Kass tweeted that he expects a reversal day this week, as he sees way too much bullishness out there. We just saw a huge negative in the indexes, which looks to be slowly but surely being bought back, but Kass doesn't believe this will last for long. If investors believe Kass' thesis, there are a myriad of ways to play it, either by going short index ETFs SPY, DIA or specific stocks, such as high flying names like Apple AAPL or Netflix NFLX. Kass is a columnist for TheStreet.com. Disclosure: no position in names mentioned.