Sam Wilson often goes to the horse races, participates in his state's lottery, and invests heavily ...

Events sanctioned by the federal and state governments are not illegal activities and therefore do not constitute gambling, which is an illegal activity. The horse races, the state lottery, and Wall Street investments are such federally and state-sanctioned activities.
The element of chance is often the pivotal point between activities of skill and activities deemed to be gambling. A football pool would be considered gambling because it is based on luck or chance and the elements of consideration and a prize are present. Participating in a football pool would be an illegal activity. The same illegality can be found in a raffle situation, in which a person can receive a prize by chance after purchasing a raffle ticket. Wilson would be well-advised to decline to participate in either of his recently-encountered gambling opportunities.

A plus for you my friend