Consider the Federal Reserve the Starship Enterprise of monetary policy: It went where no central bank had gone before, and now must plot the journey home.
The Fed already has begun one leg of the trip, as it has started raising interest rates from financial crisis-era lows. Now, it is preparing to embark on what could be the more perilous part — shrinking the $4.5 trillion of bonds it holds on its so-called balance sheet.
In an effort to jump-start the economy out of the financial crisis and the Great Recession, the Fed instituted three rounds of bond buying aimed at getting the financial markets going again and generating what officials call a "wealth effect" that would spread through the economy.
While it may sound like just arcane monetary talk, the stakes are high for both investors and consumers.
Get it right and the Fed will have pulled off what its critics thought impossible, namely embarking on unprecedented intervention in the markets with little consequence.
Get it wrong and the fallout could be dramatic, including a sharp rise in interest rates and tumult in the stock and bond markets.
The Fed on Wednesday is expected to provide more clues about when the operation will begin. In the obtuse world of Fed-speak, central bank watchers are looking for whether the official post-meeting statement changes the language from balance-sheet reduction expected before the end of the year to "relatively soon."