Given the confusion about Operation Twist, here's an explanation.

What is Operation Twist? Basically the Fed can’t reduce short-term interest rates any further—they’re already at zero. So they want to reduce long-term interest rates instead. They do this by buying long-term bonds. When you buy more of something, you raise the price. And when you raise the price of a bond, you lower the interest rate. So what the Fed is doing, is lowering long-term interest rates.

How does the Fed pay for these bonds? With QE1 and QE2, the Fed effectively just printed the money. (They “expanded their balanced sheet.”) Instead, they are selling short-term bonds, and using the proceeds to buy the long-term bonds. Now selling a bunch of short-term bonds will—usually—lower their price, raising short-term interest rates. That’s why people call this “Operation Twist”—it should “twist” the yield curve—lowering long-term interest rates (which is what matters when you buy a house, or when a firm borrows to buy new machinery), but it also raises short-term interest rates.

Raising short-term interest rates is a bug, not a feature. But fortunately, this time, the effect on short-term interest rates will be small. Why? The Fed has already committed to keeping short-term interest rates near zero for the next couple of years. And so given this commitment, the 2-year bond will also be close to zero.