As I pointed out earlier, the governors don't always contemplate interest rate hikes and they happen anyway because of changes to market conditions and unforseen situations.
Let's move on now to the QE program, which is the massive purchase of government securities by the central bank.
You said a moment ago that your bank actually sells these securities to the marketplace and then buys them right back from the same investors to whom you sold them. What is to stop an investor from profiting off the difference between the price of a government bond or treasury that you sell them and the price you pay to buy them right back?