Sorry, I couldn't find pricing data for that day. The closing price for Amazon (AMZN) on July 31, 2015 was $26.81. It was down 0.5% for the day. The latest price is $249.42.
DATE
OPEN
HIGH
LOW
CLOSE
VOLUME
July 31 2015
$26.95
$27.14
$26.73
$26.81
60,511,959
Daily pricing data for Amazon dates back to 5/15/1997, and may be incomplete.