The collapse of Lehman Brothers sent investors scrambling for the safety of cash and government debt, pushing overnight US interest rates far above the Federal Reserve's target and intensifying fears about systemic risk.
The Fed funds rate soared above its 2 per cent target and at one stage was quoted at between 6 per cent and 8 per cent. The Fed responded with back-to-back injections of $20bn and $50bn but could only bring the overnight rate back down to between 3.5 per cent and 4 per cent by midday.
Investors anticipated that the Fed would cut the overnight rate to 1.75 per cent at its meeting today, sending the yield on the policy-sensitive two-year note down 33 basis points to 1.89 per cent.