I thought 7/4/2007 was a holiday and all US markets closed. But the historical data on Yahoo Finance showed the following trading results for DIA on 7/4/2007: Jul 4, 2007 135.27 135.27 135.27 135.27 7,521,000 125.51 Is this right? Does this mean that all historical data of DIA would be a day off since 7/4/2007? Is there any other source for historical stock data? Thanks for any suggestions.