Sorry, I couldn't find pricing data for that day. The closing price for the S&P 500 (GSPC) on December 30, 2016 was $2,238.83. It was down 0.6% for the day. The latest price is $5,923.75.
DATE
OPEN
HIGH
LOW
CLOSE
VOLUME
December 30 2016
$2,251.61
$2,253.58
$2,233.62
$2,238.83
2,670,900,000
Daily pricing data for the S&P 500 dates back to 12/30/1927, and may be incomplete.