| Abbreviation | Definition |
|---|---|
| XYL | Xylem Inc. |
| XZL | Select Therapeutics, Inc. |
| XZL | Select Therapeutics, Incorporated (de-listed) |
| XZL | Select Therapeutics, Incorporated (de-listed) |
| Y | Alleghany Corporation of Delaware |
| YB | Youngstown Steel and Tube Company (delisted) |
| YCC | Yankee Candle Company, Inc. |
| YCT | Yorkshire Capital Trust I |
| YES | Yankee Energy Systems, Inc. |
| YEXT | Stock symbol for Yext, Inc. |
| YGP | Yeoman Group, P. L. C. |
| YGP | Yeoman Group, P.L.C. |
| YLD | Morgan Stanley Dean Witter |
| YLH | Morgan Stanley Dean Witter |
| YLT | Morgan Stanley Dean Witter High Income Fund II |
| YNR | Young & Rubicam, Inc. |
| YNR | Young & Rubicam, Incorporated |
| YPF | Y P F Sociedad Anonima, S. A. |
| YRK | York International Corporation |
| YSB | Salomon Smith Barney Holdings I |