After recovering from an initial jolt, U.S. stocks, bonds and the value of the U.S. dollar drifted through a quiet Monday following the latest reminder that the U.S government may be hurtling toward an unsustainable mountain of debt.

The S&P 500 edged up by 0.1% after Moody’s Ratings became the last of the three major credit-rating agencies to say the U.S. federal government no longer deserves a top-tier “Aaa” rating. The Dow Jones Industrial Average added 137 points, or 0.3%, and the Nasdaq composite inched up by less than 0.`%.

Moody’s pointed to how the U.S. government continues to borrow more and more money to pay for its expenses, with political bickering making it difficult to either rein in Washington’s spending or raise its revenue in order to get its ballooning debt under more control.

They’re serious problems, but nothing Moody’s said is new, and critics have been railing against Washington’s inability to control its debt for many years. Standard & Poor’s lowered its credit rating for the U.S. government in 2011.

Because the issues are so well known already, investors have likely already accounted for them, according to Brian Rehling, head of global fixed income strategy and other analysts at Wells Fargo Investment Institute. They’re expecting “limited additional market impact” following the initial reactions to the Moody’s move.

Stocks and U.S. government bond prices at first fell sharply early in Monday’s trading, but they trimmed their losses as the day progressed. The S&P 500 went from a loss of 1.1% to a modest gain of 0.2% before drifting through the afternoon.

The move by Moody’s essentially warns investors globally not to lend to the U.S. government at such low interest rates, and the yield on the 10-year Treasury briefly jumped above 4.55% early Monday morning. That number shows how much in interest the U.S. government has to pay in order to borrow money for 10 years, and it was up sharply from 4.43% late Friday. But it later regressed to 4.45% as more calm returned to the market.

The yield on a 30-year Treasury bond briefly leaped above 5% before likewise receding, up from less than 4% in September.

The downgrade by Moody’s comes ahead of a tense period for Washington, where it’s set to debate potential cuts in tax rates that could suck away more revenue, as well as the nation’s limit on how much it can borrow.

— Associated Press