Or investors bailing out of stocks and increasing demand for bonds, thereby lowering interest rates, or investors believing that the fear of fed tapering is overblown, resulting in interest rates going lower, or the economy going into the tank again, so the Fed holds interest rates low indefinitely, or... The point is that nobody knows what will happen in the future, and the market has already priced in everybody's best guess. If a further decline in bond prices was a sure thing, that further decline would have already happened, because nobody would buy something guaranteed to lose money.