S&P and Moody's are both considering downgrading the planemaker to junk. If they do, much of Boeing's $52 billion in outstanding long-term debt would be ineligible for inclusion in investment-grade indexes.
The average yield in the U.S. investment-grade and high-yield bond markets fell following the Fed's move, making borrowing more attractive for issuers.
Borrowing costs have become compelling, as markets are already pricing in expectations for reduced interest rates. And several external factors could reverse that trend.