HZNP - I have been out all day. Just now checking in. I apologize for not aswering earlier. I will repost something I sent in a PM yesterday responding to this same question. I made a few edits for the sake of clarity.
"I am no TA wizard but there are some obvious factors. Some are simple logic. HZNP ran from a close of 3.97 on 6/11 to close at 8.30 on 7/2 (edit: It doubled in less than 3 weeks). RSI on 7/2 was 93.71, Fast stoch 96.43. It rode the upper Bollinger band all the way up to 7/2. (Edit: all these indicate that) HZNP was way over bought technically. IMO and FIW this is a retracement and consolidation on lower volumes with profit taking as you observed on diminishing volumes. This is healthy IMO. Again, I am no technician. I know a little and all I can share is the little I know or see or think I see."
Trade, Wrinks, anybody (which means most everybody) with stronger TA chops than mine please comment if I am off anywhere in here. What I expressed was the most basic of TA that I have learned with the help of people on this and the GoodFellas board. If I intimated in any way that I had anything other than rudimentary TA knowledge I apologize and want to correct that error immediately. Thanks to $heff and all on this board who work to make it such a great place.