Participate in every bounce, not exit... Only participate.. You cannot predict the future so if you see that many alts are being dropped all at the same time because something like BTC is soaring, then you may want to exit for smaller profits, but you must atleast participate in the bounces.. that means you layer some sells at or just above your break even price.. take some profit.. work your position, so that if does drop suddenly again you are in a better position to average down more..
yes, you work the position.. no one can predict whats going to happen, so you make sure that you atleast participate in every bounce.. and read the signs.. if it pops into profit fast, then you sell fast.. if it grinds up slow, then you sell slow, little by little.. theres also volume to consider, but thats more detail than necessary to explain (less important)