If the federal funds futures price is lower than the spot price, it means that they expect the Fed to raise interest rates.
If the futures price of the federal funds is higher than the spot price, it means that they expect the Fed to cut interest rates.
Supplement: Federal funds futures are based on the federal funds rate. The pricing principle of federal funds futures is to subtract the expected average federal funds interest rate during the contract period from the base of 100. Although this pricing mechanism is subtraction, it is essentially a simplification of the traditional discounted present value pricing method. Therefore, if the interest rate is expected to rise in the future, the price of federal funds futures will decrease; On the contrary, the price rises.
In addition, the federal funds rate is not similar to the deposit reserve ratio of the central bank as you said, but the overnight interbank lending rate between American banks, so the federal funds futures can be used to hedge this interbank lending, which is a market interest rate.
It seems that there is no such futures product by using the central bank's deposit reserve for futures hedging. Besides, how does this kind of futures work? It seems impossible.