During the start if bull, altcoins start pumping slowly and continuely keep continue pumping. And then when bull getting more stronger with days, speed of increasing of altcoins will also get faster than before. If you buy altcoins from top then you can literally earn 5x-10x of increasing of your portfolio even more. And there are many under valued coins, those will pump a lot more then speculation but so risky
Altcoins don't rise slowly, they are very volatile especially during the bullrun, they can rise as fast as within some minutes and also dumps within the same, this is what we should understand about them, they can be unpredictable in so many ways, they are so highly volatile, when the market begin to rise, they are the first that often experience this surge and when it falling as well, they fell along so fast and so big.