What is going on with Interest Rates and the markets?

In mid-September 2023 forward rates (3 month Compounded SONIA) where predicting interest rates would dip below 4% in September 2027 but now the market is predicting that rates will dip below 4% in November 2024!

Where does the massive surge in optimism come from? I really cannot fathom what's driving this euphoria at the moment. The US Stock Market hit a record high on Friday!

I see the spectre of inflation remaining for some time to come with Central banks having a debt crisis to address. Anybody got any answers??