There are days where trying to explain the stock market might as well amount to a day spent scratching your head. Apple is set to crush the holiday season and deliver impressive fiscal quarter results, even by there standards. There is very little Apple seem to be able to do aside from introducing a much begged for new product line. The market seems intent on holding Apple down until this happens. My advice is to get in while you can under $600 and watch your profits soar the moment Apple announces even a hint of anything coming soon on the horizon.
Twitter is soaring faster and higher than any reasonable person could have predicted so soon after their IPO. The company hasn't even announced anything detailing financial positives or momentum. The market is clearly in a feeding frenzy for hot stocks to keep the market momentum going. Driving the market higher as a whole seems to be benefiting Twitter greatly. I would not take part in this feeding frenzy. Stay calm and let the dust settle after the first fiscal quarter report. At that time we will have a much better understanding of how Twitter is monetizing the user base and the effect the new ad initiatives are having.
Disclosure: I have no positions in any stocks mentioned, and no plans to initiate any positions within the next 72 hours.