Imagine a carmaker that just sold €100 million of bonds but won’t need the cash for a factory until next month. Or a pension fund that has to pay benefits on Friday but will receive contributions on Monday. Both need a safe, liquid place to park or borrow money for a very short time — a few days, perhaps a few months. That’s the money market: a huge, almost invisible marketplace where governments, banks, and companies lend and borrow large sums for less than a year.