Gulfport Energy, Saia, FXCM in S&P index changesOct. 10, 2013 5:39 PM ET|About: Gulfport Energy Corporation (GPOR)|By: Carl Surran, SA News Editor Gulfport Energy (GPOR) will replace WMS Industries (WMS) in the S&P MidCap 400, and Saia (SAIA) will replace GPOR in the S&P SmallCap 600 after the close of trading Oct. 17. FXCM (FXCM) will replace Kaydon (KDN) in the S&P SmallCap 600 after the close of trading Oct. 15. WMS and KDN are being acquired in deals expected to be completed soon. SAIA +1.7%, FXCM +1.5%, GPOR +0.8% AH.