The principle behind the rule of law is that citizens must understand the law
nobody is above the law
Government must enforce the law
citizens must accept the law

Rule of law, the mechanism, process, institution, practice, or norm that supports the equality of all citizens before the law, secures a nonarbitrary form of government, and more generally prevents the arbitrary use of power

the answer is: must pay taxes on profits

since it is considered as a part of your income, profits from investments is eligible for tax payment.

the tax from your investment could be influenced by how long you decided to sell it. united states promotes keeping your investment for long term period. so, the tax rate for investments that you sell in less than one year is typically higher compared to investments that you sell in more than one year period.

four sitting presidents have been assassinated while in office but the first was abraham lincoln,