Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Indicators a stock is part of a pump and dump scheme?
Note: the answer below is speculative and not based on any first-hand knowledge of pump-and-dump schemes. The explanation with spamming doesn't really makes sense for me. Often you see a stock jump 30% or more in a single day at a particular moment in time. Unlikely that random people read their emails at that time and decide to buy. What I think happens is the pumper does a somewhat risky thing: starts buying a lot of shares of a stock that has declined a lot and had low volumes during the previous days. As the price starts to increase other people start to notice the jump and join the buying spree (also don't forget that some probably use buy-stop orders which are triggered when the price reaches a particular level). Also there should be some automatic trading involved (maybe HFT firms do pump-and-dumps) as you have to trade a big volume in a relatively short time span. I think it is unlikely to be done by human operators. Another explanation would be that there is a group of pumpers (to spread the risk so to speak). Update: As I think more of it, it is not necessary to buy "a lot of shares". You could buy some shares, sell them to another pumper and buy from them again at a higher price in several iterations. I think this could also work if you do it fast enough. These scheme makes sense only you previously bought many shares at the low price, possibly during several weeks. Once the price is pumped high enough you can start selling the shares you previously bought (in the days preceding the pump).