Sorry, I couldn't find pricing data for that day. The closing price for Berkshire Hathaway (BRK.A) on May 15, 1981 was $525. The latest price is $746,095.
DATE
OPEN
HIGH
LOW
CLOSE
VOLUME
May 15 1981
$525.00
$540.00
$525.00
$525.00
100
Daily pricing data for Berkshire Hathaway dates back to 3/17/1980, and may be incomplete.