| Underlying instrument | |
| 1. In options, the security that must be delivered if a put or call option is exercised. 2. In equities , the common stock that underlies certain types of securities such as warrants and convertible bonds. Aka as Underlying market. | |
| Underwriter | |
| Someone, usually a city institution, who agrees to buy any shares in a new issue not purchased by the public. | |
| Unit trust | |
| A portfolio of various investments divided into units and managed by professionals. The value of the units does not depend on supply and demand but on the underlying value of the portfolio. | |
| Universal Stock Futures | |
| futures contracts on individual equities. These are traded on Euronext.LIFFE. | |
| Unsecured loan stock | |
| A fixed interest stock not secured by assets. | |
| Up bet | |
| a bet that will be profitable for every tick that a price rises. Also called a buy or going long. As opposed to a down bet. |