Yeah, pretty well that easy. I've spent a few hours playing with the market, it's pretty reactive to your actions.
Buy ammunation early. Like start of the game early, the more you buy, the better the stock performs.
*shrug*
Basically anything you think would affect the market in real life does in the game, just you have the power to control it in game.
Getting busted/wasted barely does anything to the cash in your pocket, does absolutely nothing to your portfolio.