The bond market may have brushed off Moody's US credit downgrade, but it's still showing growing unease over the country's deepening fiscal crisis.

Treasury yield rose while Wednesday’s $16 billion auction of 20-year bonds garner more attention than usual in the context of the 10-year rising back above 4.5%.

U.S. Treasury yields ticked higher on Wednesday as investors closely monitored discussions on the budget bill and federal deficit.