Borrowing rates skyrocketed on Tuesday in a corner of the markets the public rarely notices but that is critical to the functioning of the global financial system. The spike in overnight borrowing rates forced the New York Federal Reserve to come to the rescue with a special operation aimed at easing stress in financial markets. It was the NY Fed's first such rescue operation in a decade, the last occurring in late 2008. "It's unprecedented, at least in the post-crisis era," said Mark Cabana, rates strategist at Bank of America Merrill Lynch. On Tuesday morning, the NY Fed launched what's called an "overnight ... (full story)