You take to the road because you want to reach a destination, which is your reward. When you invest, the risk is that of loss. The reward is the return you might get. This is actually a simple relationship, which is often misunderstood by many people. High risk does not necessarily mean you will get a high reward.
High risk means the potential for loss is high.
At the same time, the potential returns can be high. If you are taking high risks, it is important to decide before hand when you are going to say quit. Most people take high risk without knowing it, lured by only the potentially high reward. Such actions usually end up in disasters. If you want to climb mount Everest, you should be properly equipped to do so.