Both cases are manipulation. You move PAL up a lot and day traders will chase it and then you bring it down and day traders will sell.
In the case of SWC we see the same daily tarde pattern again and again. Pull up in the morning, then knock down and keep it low for a good part of the day, and then in the last half hour, the shorts try to cover as much as possible. Pull the stock up and then knock down makes it easier to prompt the weak hand longs to sell, as it create a "regret" sentiment amongst weak hand longs.
I bought some this morning when it was up about 12%, and now it is up 20%. Yesterday it went up 30% or something really big; should i sell now or wait a few days for another large move (palladium, plat., gold have all been having big days too)