Strong U.S. economic data and a hawkish Federal Reserve shift have driven 5-year Treasury yields sharply higher in September 2026, with the benchmark rising from early-month levels near 4.5% to close at 5.05% on September 28. The September S&P Global composite PMI surged to 58.4, the highest in over five years, alongside robust employment and backlog readings, while the Fed's recent 25-basis-point hike to a 3.75-4.00% fed funds target range and signals of further tightening have lifted real yields and reduced rate-cut expectations. Weak demand at recent Treasury auctions, including the 5-year note pricing above 5% for the first time since 2007, reflects supply pressures from elevated deficits and a $40 trillion debt load. With the month nearly complete, these factors suggest limited scope for further declines absent a rapid reversal in growth or policy signals.