The Philadelphia Stock Exchange is the oldest stock exchange in the United States. Located in Philadelphia, Pennsylvania, it was founded in 1790. It merged with the Baltimore Stock Exchange in 1949 and the Washington Stock Exchange in 1954.
On October 22, 1981, trading was halted on both the Chicago Board of Trade and the Philadelphia Stock Exchange after anonymous callers said bombs had been placed in those buildings.
Additional meaning of Philadelphia Stock Exchange:
Philadelphia Stock Exchange (PHLX), now known as NASDAQ OMX PHLX.