 Shares of CoreCivic NYSE: CXW, a real estate investment trust REIT that owns jail and halfway-house properties tied to the criminal justice system, jumped more than 10 in early trading Wednesday and remained up 7.3 at 11:15 a.m. EDT today. This morning, SP Dow Jones Indices announced that tiny CoreCivic will replace even tinier offshore driller Valaris NYSE: VAL on the SP SmallCap 600. CoreCivics addition to the SmallCap 600 index doesnt take effect until Aug. 17, after which date it can be assumed that mutual funds and ETFs that track the composition of the SmallCap 600 will buy CoreCivic shares so that their holdings accurately reflect the index. 