Treasuries ended the day mixed Monday, according to S&P Marketscope. In the afternoon, Fed Governor Bies was fairly upbeat on the economy, and the stock market was stable, according to Informa. Both prompted selling in the bond market, with 2-years at one point sliding into negative territory. The selling was led by hedge funds and profit takers as the market fears a strong PPI tomorrow. Earlier in the day, central banks and speculators were buying Treasuries, while hedge funds were selling and booking profits, said Informa.