In advance I thank for answers.
you should always be worried about dumps when you are investing in altcoins because that is the part and parcel of them. you can not have a pump without a dump!
at this point i honestly don't consider these altcoin prices to be the "bottom" so i would expect more dumps but you will never know.
as for your main question, in the next 3 months we will get closer to summer and by then we usually see a more active altcoin market. some even claim it is because school kids come back to the market! in any case we might see some pumps then.