I want to be able to price a risk parity index using the following prompt expiry futures contracts available from ECBOT and GLOBEX. Using a synthetic portfolio priced by adding the CASH VALUE of the Ultra-Bond contract and ES.
Then, using the front month contract midpoints, we have
Risk Parity Portfolio = 1000 * UBZ22 + 50 * ESZ22
This is a simple (naive) approximation for a portfolio invested in long dated treasuries and US large cap equities.
So, quants on the stack, give me some simple multipliers or tell me why these weights aren't right for a 60/40 portfolio approximation.