you can make a profit from it
Yes it can. There's a so called whale group who can do that and also some big people in the bitcoin world. But I noticed that because of many bitcoin adopters today unlike in the past, manipulators are having a hard time to do such a move because moreover more people that not part of the "manipulators" are joining the bitcoin madness.
yeah, this issue exists as of today but hopefully it can be resolved in the future as the number of users grow in number and bitcoin becomes more spread and not just in the hands of few big pockets.
this will make the effect of whales and negative propaganda less effective so hopefully it would lead to a more stable market.