"He who sells what isn't his'n, Must buy it back or go to prison"

Daniel Drew’s aphorism encapsulates the inherent risks and ethical dilemmas within financial markets, particularly in practices such as short selling and speculation. The phrase draws attention to the fundamental principle that one cannot ethically or safely profit from selling something over which one lacks legitimate ownership. When engaging in such conduct, the individual incurs an obligation: if circumstances shift or the true owner demands their due, repayment or restoration becomes mandatory. Otherwise, legal repercussions, incarceration or punishment, are inevitable.

At its core, the saying is a metaphor for the broader concept of accountability and the necessity of responsibility in commerce. When someone sells "what isn't his'n", he is venturing into a space of borrowed trust. In financial markets, particularly in 19th-century Wall Street where Drew was a prominent operator, this often referred to practices like shorting stocks, selling shares one does not own in the hope of buying them later at a lower price. The risk is twofold: if the price instead rises, the short-seller must procure the stock at a higher cost (effectively “buying back” what he’s committed to deliver). Should he fail to do so, consequences can become legal rather than merely financial.

Drew’s succinct rhyme also functions as a moral maxim. It implicates individuals and institutions who, motivated by profit, disregard the legitimacy of their claims or the rights of others. The balance of markets and society relies on trust and propriety; when these are breached, systemic risk and injustice follow. Thus, Drew distills a lesson on prudence: one must transact honestly and uphold obligations, or face inevitable restitution or censure. The pithy warning reverberates beyond Wall Street, serving as an admonition in business, law, and personal conduct, underscoring that shortcuts and deceit may occasion immediate gains, but seldom without eventual and often severe costs.