what is a s and p ptp index participation rate

The closing price for the S&P 500 (GSPC) yesterday was $5,912.63. It was up 0.7% for the day (up 0.3% from previous close).

DATE OPEN HIGH LOW CLOSE VOLUME
May 15 2025 19:00
$5,912.63
$5,912.63
$5,912.63
$5,912.63
May 15 2025 18:30
$5,909.35
$5,917.74
$5,908.86
$5,911.71
135,652,000
May 15 2025 17:30
$5,922.00
$5,922.05
$5,901.49
$5,909.35
262,250,000
May 15 2025 16:30
$5,907.14
$5,924.21
$5,904.00
$5,921.96
266,891,000
May 15 2025 15:30
$5,898.55
$5,913.83
$5,895.84
$5,907.09
307,783,000
May 15 2025 14:30
$5,872.98
$5,903.28
$5,867.82
$5,898.37
409,624,993
May 15 2025 13:30
$5,869.82
$5,885.54
$5,865.16
$5,872.95
561,292,468
Daily pricing data for the S&P 500 dates back to 12/30/1927, and may be incomplete.