Ten years after the financial panic, the architects of the rescue policies are taking a victory lap. We won’t relitigate the immediate panic response, some of which we supported. But there is one policy whose outcome is still uncertain: The Federal Reserve’s near-decade of unprecedented zero-interest rates and bond buying. Is the October correction in stocks, including Wednesday’s 3% plunge, telling us that this bill is now coming due?

The final payments on any Fed monetary cycle aren’t merely the results when interest rates...