Also, FOMO (Fear of Missing Out) is a normal feeling of traders when coins are actually dumped big time.
Here's how. We all know that media plays a big role in the dump value of some coins.
Accdg. To this site
(contains also tips on trading)
BUY THE RUMOURS. SELL THE NEWS (not literally)
When media talks often about the dump and publish articles, then that is the RIGHT TIME TO EXIT.
News, rumours, speculations could have a big impact and can affect the price of altcoins. They concide the price movements resulting in pump and dump.
Believe me, I did that and it really works. Prevents deficits and prevents loss of investment.
The best time to exist trading is all based upon each individual and respective situation. From my point of view you can exist the trade when you gained much profits. As you said media plays a major role where both the pessimist and optimistics new flow through it. But as a experienced trader we should make a technical analysis of these news for the further move in our trading.