what is the correlation coefficient between berkshire hathaway and sandp 500 over the past 5 years

Between October 10, 2020 and October 10, 2025, Berkshire Hathaway (BRK.B) has returned 129.2% and the S&P 500 (GSPC) has returned 92.4%.

DATE the S&P 500 Berkshire Hathaway
October 2025
$6,735.11
$496.74
September 2025
$6,688.46
$502.74
August 2025
$6,460.26
$502.98
July 2025
$6,339.39
$471.88
June 2025
$6,204.95
$485.77
May 2025
$5,911.69
$503.96
April 2025
$5,569.06
$533.25
March 2025
$5,611.85
$532.58
February 2025
$5,954.50
$513.83
January 2025
$6,040.53
$468.67
December 2024
$5,881.63
$453.28
November 2024
$6,032.38
$483.02
October 2024
$5,705.45
$450.92
September 2024
$5,762.48
$460.26
August 2024
$5,648.40
$475.92
July 2024
$5,522.30
$438.50
June 2024
$5,460.48
$406.80
May 2024
$5,277.51
$414.40
April 2024
$5,035.69
$396.73
March 2024
$5,254.35
$420.52
February 2024
$5,096.27
$409.40
January 2024
$4,845.65
$383.74
December 2023
$4,769.83
$356.66
November 2023
$4,567.80
$360.00
October 2023
$4,193.80
$341.33