Over the multiple decades (too many to count) that I have taught Securities Regulation, the most stable, unchanging part of the course was the chapter on "What Is a Security." All law professors teach SEC v. Howey, 328 U.S. 293 (1946) and its three-part test: Was there (1) an investment of money or property (2) in a common enterprise (3) with an expectation of profits predominantly from the efforts of a promoter or other third party?