>>are you inclined to sell some here in anticipation of a swoon
I really don't trade stocks much based on stock price movements - if I like a stock, I sit with it, for years if necessary. I do rebalance my portfolio if a stock has a big run though, and I'm pretty firm on selling any significant losers held in a taxable account prior to year end.
When I do trade, my preference is to buy biotechs on days when the overall market it weak and sell when the overall market is strong. (Psychologically that's hard to do I know, and I don't always succeed in following my own advice).
Peter