Nobody knows this for sure. What I can tell ypu is that at some point we will probably see a parabolic rise with the market. Not sure which coins will go the most but it happens every cycle and we haven't seen it yet. So with that being said I wouldn't be scared of a pullback and actually would welcome it. Cost average in when it comes down and be ready for the real bull to kick in
Yep, there are already a lot of altcoins these days and no one knows what altcoin will go pump or dump. There are already a lot of different bases, like some token unlocks, some fud to different altcoins, or some big updates from different projects.
Some also are pumping or dumping because of manipulation.
That's altcoins for you and we should enjoy it while it lasts. Altcoins are many, so their behaviours, actions and inactions will definitely vary because many things are different with them. Their news, and community size are different, and so are the brains behind them. The upgrade/scalability, the hypes, and even the marketing by some vary, so we can't expect the same reaction from them. This is why it is good for us to vary the coins/tokens we buy, so that we will not miss out, and when they make huge corrections, it will not affect us as such.
And yes, no doubt, many altcoins are being manipulated. This is obvious on the trading charts with the way they behave. Some would be pumped so fast and be dumped in that regard as well. It's all about the relevance of the coin and its market capitalization. The lower the market cap, the more susceptible they can be manipulated. Above all, what I do now is to invest in the coins that are newly listed by notable exchanges. They are mostly stable and performing well these days.