Personally, I panicked a bit last week as I watched the price plunge.
I have faith in the long term potential of bitcoin. As such, a price drop is not a reason to panic, it's a reason to get excited and celebrate. The more the price droped, the more bitcoins I bought (cheap coins! Yeah!).
But the way the price has slowly crept back up is incredibly reassuring, making me want to invest even more.
Having dumped all my available cash into bitcoins as the price dropped, I've got nothing more to invest now that the price has recovered. Instead, I took advantage of the rise to sell those cheap coins at a profit.