Sorry, I couldn't find pricing data for that day. The closing price for Walmart (WMT) on May 15, 2020 was $39.00. It was up 2% for the day. The latest price is $102.10.
DATE
OPEN
HIGH
LOW
CLOSE
VOLUME
May 15 2020
$38.23
$39.00
$38.12
$39.00
31,770,000
Daily pricing data for Walmart dates back to 8/25/1972, and may be incomplete.