I'm not really understand how treasury bond futures work. Take the 10-Year T-Note Futures. Currently, it lists that the June 2024 one is settling for $109,000 (and each T-Note has a face value of $100K).
If I bought one of these, that means in June I am entering into a futures contract where I buy a T-Note and post up some sort of margin (and then my PnL are marked-to-market after that). But this T-Note I bought, when does it expire? June 2024? June 2034? How do I know its coupon rate?
The way bond futures work, there will be several different Treasury bonds that are eligible for delivery on the futures expiry date. You won't know the exact coupon, but they will all have maturities within 6 1/2 to 8 years for a 10-Year future. The treasury will sell you the bond that has the lowest future value (the "Cheapest to Delivery" bond), which might not necessarily be the one with the lowest coupon, depending on the maturities. You could look at the coupon rates of current treasury bonds in that maturity range to see what kind of coupon you could expect.
If you buy a future and do not close it out (i.e. sell it before expiry) - you will be obligated to buy the treasury bond that is delivered. The Futures trade will require you to post margin to cover any losses, but I do not see any indication on the CME site that you can use margin to buy the bond - if you do not have the cash to buy the bond you will likely be forced to sell the future before expiry instead.
Note that bond futures are more commonly used for hedging interest rate risk or speculation rather than actually buying bonds, and are much more likely to be closed out before maturity (unlike commodity futures which have larger physical settlement rates due to the costs to store physical commodities).
See The Basics of US Treasury Futures for more details on specific contracts.
