We do not have a free market in interest rates today. We have not had one since the creation of the Fed in 1913. The Fed began buying bonds almost immediately, which pushes up the price and hence pushes down the interest rate.
However, as I discuss in my theory of interest and prices, the Fed creates a resonant system with positive feedback loops. It wants lower rates (so the government can borrow more, more cheaply) but it gets a destabilized rate which moves higher. At first. Then lower, much lower. Then higher. Then lower.
The Monetary Metals project is developing the first free market to set a rate in 105 years. I discuss it on video.