Anybody know why sites such as Yahoo and Google Finance show S&P opening prices higher than what actually occurred? For example, on Friday the index opened (gapped) down on the jobs report, yet Yahoo shows Friday's open at 1391.51: http://finance.yahoo.com/q/hp?s=%5EG...torical+Prices

Was that the true open? Obviously no one could have bought an ETF near that open price for an obvious short. Thanks.