A record number of blue-chip firms are tapping the US corporate bond market, making it the busiest single sales day on record. On Monday, 29 companies, including Ford Motor Credit Co. and Fifth Third Bancorp, issued bonds to take advantage of lower borrowing costs ahead of the US presidential election. This rush comes as corporate borrowers aim to get ahead of potential market volatility and interest rate spikes expected around November due to the Federal Reserve's upcoming rates decision. The Treasury coupon auctions are set to resume on September 10, with a $199 billion coupon settlement expected. The August index return is 1.3%, and the year-to-date return is 2.6%.