Which rule limits bank risk, specifically pertaining to proprietary trading?

The Volcker Rule is designed to limit the risks that banks take on by specifically addressing proprietary trading. This regulation, named after former Federal Reserve Chairman Paul Volcker, prohibits banks from engaging in proprietary trading, which is when a bank trades financial instruments for its own profit, rather than on behalf of its clients. The intention behind this rule is to prevent banks from taking excessive risks that could threaten their stability and, by extension, the wider financial system. The aim is to reduce the likelihood of a repeat of the financial crises, where banks’ risky trading activities led to significant financial instability.

The other options refer to different aspects of financial regulation that do not directly pertain to proprietary trading. For instance, the Access Rule relates to the availability and conditions of access to financial markets, the Sub Penny Rule addresses the pricing of trades in certain markets, and the Order Protection Rule pertains to the execution of orders in securities markets to ensure better prices for investors. None of these directly limit bank risk in relation to proprietary trading like the Volcker Rule does.