apan's super-long-dated bonds briefly changed course on Friday to trade lower after an auction of 20-year bonds drew weak demand due to fiscal concerns. Here are a few details: The 20-year bond yield reversed course to rise as high as 3.565%. The yield was last down 3 bps at 3.535%. Yields move inversely to bond prices. At the auction, a measure of demand called the bid-to-cover ratio, which gauges total bids against the amount of securities on offer, fell to 2.97, the lowest since May 2025, from 4.01 at the previous sale in May.