Looks like you called it. When a stock price rises swiftly on no real news you get a bunch of day traders jumping in. When they see a peak many will sell off for a nice profit....possibly move on or wait until it drops enough to buy up for another run. This is why you see pullback. One of two things happen...either it peaks and pulls back down and keeps going down or it cycles with dips and rises often going higher on each rise. The later is more common when there is news or an article released favoring buying the stock. If the price rises drastically with no catalyst then it is often the former. This is based on my experience though.
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