Your brother is a physician who does not have the time to manage his own money. Knowing that you hav

Your brother is a physician who does not have the time to manage his own money. Knowing that you have an interest in investments and have taken a class in technical analysis, he asks you to develop a trading system for him. Before you agree to take on this job, you want to make sure that he understands the concept of risk. How would you explain risk to him, especially as it is related to using a system for investing?