From Wikipedia…the S&P 500 Index began in its present form on March 4, 1957.
“Standard & Poor’s introduced its first stock index in 1923. Before 1957, its primary daily stock market index was the “S&P 90”, a value-weighted index based on 90 stocks. Standard & Poor’s also published a weekly index of 423 companies. The S&P 500…
Stocks
