Yes it is true. Even me to be honest. When I see my altcoin investment is falling down, I will sell it all because i don't want to see it into serious loss. That is my worst strategy on this fall situation.
Not all are in panic because of this situation in the market, some of the major investors are taking this opportunity to invest in those who have potential coins at in a cheap prices. For me it's better to rest of monitoring the market, and wait for the well condition.