| Abbreviation | Definition |
|---|---|
| PSAI | Pediatric Services of America, Inc. |
| PSAX | P S A, Inc. |
| PSAXE | P S A, Inc. |
| PSBI | P S B Bancorp, Inc. |
| PSBT | Penn Security Bank & Trust Company |
| PSCKF | PlayStar Wyoming Holding |
| PSCO | ProtoSource Corporation |
| PSCO | ProtoSource Corporation (de-listed) |
| PSCOW | ProtoSource Corporation Warrants |
| PSCOW | ProtoSource Corporation Warrants (de-listed) |
| PSCT | PowerShares S&P SmallCap Information Technology Portfolio |
| PSCT.PK | Rescon Technology Corporation |
| PSCX | P S C, Inc. |
| PSCX | PSC, Incorporated (de-listed) |
| PSCX | PSC, Incorporated (de-listed) |
| PSDI | Project Software & Development, Inc. |
| PSDI | Project Software & Development, Incorporated (de-listed) |
| PSDI | Project Software & Development, Incorporated (de-listed) |
| PSDN | Packet Switched Data Network |
| PSEM | Pericom Semiconductor Corporation |