...and how do they do it?

First, they buy and sell within their group working the SP up fast, which is relatively easy to do when a SP starts running.

Then they will actually buy and sell within their group always trying to push the SP down.

They will always put up a couple of large walls a few cents above the SP to stop it from breaking out.

They will continue this activity UNTIL there are no more SELLERS. This activity is prominent in mining stocks on the Venture Exchange and especially in penny stocks.

Skier