Today I'd like to explain what can cause large green bar to blast in trading. A few reasons may cause it and here's one. Huge orders (Either sold or purchased) as a market order. Which is why I'd always recommend huge orders submitted as a limit order, but at current market price. If you try selling 10,000 shares at market, there won't be enough orders to fill at current price, so your order will start eating away at the stack. On huge orders, you could easily fill so many that it drops the price by a few dollars. But since orders on big movers (like AMD) are always coming in, those contracts that just processed get filled back in. That literally causes a 'mini' spike either down or up, and the graph will show it.