The stock market on September 12, 1984
September 12, 1984, a Wednesday. The S&P 500 rose 0.14% to close at 164.68. Of 5,788 US stocks that traded, 1,451 rose and 1,654 fell.
The S&P 500+0.14%closed at 164.68
How big a move#20,703of 24,799 trading days since 1928
$100 in the index since$4,678price only, to September 24, 2026
Stocks that rose1,451of 5,788; 1,654 fell
Biggest companyInternational Business Machines Corporationby market value that day
Last day of trading for1stock
Biggest rises among the 500 largest companies
| Aramark Corp -cl B | +19.6% |
| Tandem Computers Inc (TDM.) | +4.8% |
| Maxus Energy (MXS) | +4.7% |
Biggest falls among the 500 largest companies
| Amp Inc (AMP) | -12.0% |
| Molex (MOLX) | -10.1% |
| Avnet (AVT) | -8.0% |
Stock moves count dividends; the index is price only. Market values after 2024 are estimates.
‹ September 11, 1984 · Every September 12 · September 13, 1984 ›
Ask the Lab what came after a day like thisHistory, not advice. How these numbers are made.