After it auctions a bond, what role does the U.S. Treasury play in determining the day-to-day price of the bond? Almost no role It sells and buys bonds to keep the market price close to the original auction price. It sells and buys bonds to keep the market yield close to the Federal Reserve's target rate. It computes and enforces the current market price of the bond, according to a calculated trajectory from the date of auction to the date of maturity. It guarantees to buy the bond back at the original auction price, if the borrower makes that request, but intervenes in no other way