When the University decided that it would take on $500 million in debt to raise liquidity on March 6, Cornell’s financial officers went to work picking a date during which the bonds would fetch the best interest rate in this dramatically fluctuating market. The coupon rate, or rate of interest on which the bonds sell, depends heavily upon events like release of jobless rates, corporate earnings reports, other assets being sold that day and religious holidays, according to Joanne DeStefano, vice president of finance.