Still, if it were that simple, the final draft would be a lot shorter than its roughly 920 pages — about as long as Dostoyevsky's "The Brothers Karamazov." The rule left to regulators the burden of finalizing the fine print.
Besides curbing proprietary trading, the Volcker Rule limits banks' investments in hedge funds and private equity funds, which are high-risk, lightly regulated investment pools.
The rule is named for Paul Volcker, a former Federal Reserve chairman who was an adviser to President Barack Obama during the financial crisis. Volcker urged a ban on high-risk trading by big banks to diminish the likelihood that taxpayers might have to rescue them, as they did after the financial crisis.
Q: Where are the complications?
A: The ban on proprietary trading isn't absolute. There are exemptions. One involves an important activity called market making. When big banks engage in market making, they use their own money to take the opposite side of a customer's trade: They buy or sell an investment to help execute the trade.
Q: Why does the Volcker Rule matter?
Because of the widely agreed-upon need to reduce the dangers that remain in the banking system. Proprietary trading has allowed big banks to tap depositors' money in federally insured bank accounts — essentially borrowing against that money and using it for investments, such as in mortgage-backed securities. When those bets soured during the crisis — especially after a wave of mortgage defaults — the banks were at risk of failing. Most survived only because of taxpayer-funded bailouts.
Q: So would banks be barred from investing the money I deposit?
A: The short answer is no. When people deposit money in a bank, they may expect the bank to use it for conventional safe investments, such as bonds. Those would still be allowed. But banks could no longer borrow against depositors' money to seek outsize returns on complex investments, like derivatives. Derivatives are investments based on the value of an underlying commodity or security, such as oil, mortgages, interest rates or currencies.
Q: How did the rule become so complicated?
A: Regulators found it hard to isolate what precisely distinguishes proprietary trading from, say, market-making. The line can be blurry.
Another challenge: No fewer than five agencies, including the Federal Reserve and the Securities and Exchange Commission, had to grapple with the rule and reach common ground.
If that weren't enough, industry lobbyists used their muscle to try to preserve the banks' trading operations. They won a round in 2011, when regulators approved a draft that exempted "portfolio hedging" from the trading ban. This meant banks could make trades for their own profit to offset the risks of either individual investments or a broader investment portfolio.