You can stop on a skateboard fast by performing power slides. Power sliding works on the principle of locking one back wheel so that it skids rapidly across the surface. This creates friction, slows down the speed and brings it down to a complete stop.
The method is very effective to stop fast skateboard but needs perfect timing to be performed correctly. It requires some practice to master the art of power sliding. A wrong move or slight mistake can break your board or injure you severely.