** Shares of AppLovin APP.O, Robinhood Markets HOOD.O and Emcor Group EME.N surge after S&P Dow Jones Indices announce their upcoming inclusion in the benchmark S&P 500, effective before the market opens on September 22
** Applovin rises 7.5% to $528, HOOD jumps nearly 7% to $109 and Emcor up about 3% at $642, in after-hours trading
** AppLovin, Robinhood and Emcor will replace MarketAxess MKTX.O, Caesars Entertainment CZR.O and Enphase EnergyENPH.O, respectively, on the index
** Up till last close, shares of APP up 51.4%, HOOD's jump 171.4% and EME's rise 37.8%, YTD
(Reporting by Apratim Sarkar)