sure, it could happen, no one knows for sure, but assuming the exchange listing stays the same people will see the price history and probably not want to list much lower than that.  crypto currency is the most volatile trading there is.  Just don't panic sell if you see it dip down, and never risk more than you can afford to lose.

edit: I will add though that there wont be any mining during the ICO.  I'd PERSONALLY expect some ICO buyers to turn around and list coins at a higher rate than the ICO price as soon as we get our hands on them, but again, this is all speculation.  That all being said, I'm not a whale or big timer by any means and I plan to purchase a decent amount if I'm able to get my order in on time.