A Checklist of arguments to consider when defending against a control person claim under the Securities Act of 1933 (Securities Act) or the Securities Exchange Act of 1934 (Exchange Act), which allow private plaintiffs to assert claims not only against those who violate the federal securities laws, but also against any entity or individual that controls the violators. This checklist offers arguments to consider at the motion to dismiss and motion for summary judgment stages when defending against control person liability claims under Section 15 of the Securities Act and Section 20 of the Exchange Act, including affirmative defenses.