It has three 'eyes' (the red, orange and green lights) and the leg is the pole holding it up. Many people beg the light to stay green as they’re approaching.
Undergraduates may get this question as feelers of their business knowledge. Insider trading describes the illegal activity of buying or selling stock based on information that is not public information. This is to prevent those with privileged information (company execs, I-bankers and lawyers) from using this information to make a tremendous amount of money unfairly.