Just a natural part of being in a highly volatile asset class. Probably unnerving if you're a day trader... I'm just in for the long haul so dips are simply an opportunity to buy more "on sale."
Just wish the overall market size (available cash on the sidelines) would grow so the alt coins don't suffer systemic sell-offs every time BTC is on the rise... we need more aggregate money IN the market, not just the same money flowing back and forth between different coins.