Does it mean bond future short seller has the obligation to buy back the physical bond via cheapest to deliver method?
Below from Kaplan
Cheapest to deliver (CTD) is a very descriptive term for a bond that the counterparty in the short position can deliver to satisfy the obligation of the futures contract. For example, many different bonds can be used to satisfy a CBOT 30-year Treasury bond futures contract. Furthermore, the short position has some choice with respect to the time of delivery.
Below from Kaplan
Cheapest to deliver (CTD) is a very descriptive term for a bond that the counterparty in the short position can deliver to satisfy the obligation of the futures contract. For example, many different bonds can be used to satisfy a CBOT 30-year Treasury bond futures contract. Furthermore, the short position has some choice with respect to the time of delivery.