WHEN the Safety-Kleen Corporation disclosed on Aug. 5 that it was guilty of large-scale permit violations in its storage of liquid hazardous wastes in Puerto Rico, investors hammered its stock.

Not surprisingly, investors have hammered Hirsch's stock, which now trades below $1, down from a high of $26 in late 1997.

Snubbing the Bank of Japan and the interest rate cut it announced yesterday, investors hammered Japanese stocks downward again today, with the benchmark Nikkei 225-stock index falling 1.57 percent, to 12,681.66, its lowest close in more than 15 years.

Already gloomy investors hammered Infineon shares down 16 percent after the announcement, and it closed at 28.85 euros ($24.65) a share in Frankfurt trading.

When Apple warned three weeks ago that its earnings for the quarter ending in June could be below the levels of a year before, investors hammered the stock, sending it plummeting $7.75, to $47.25, in one day of over-the-counter trading.

Disappointed investors hammered Raisio's stock, which closed at $7.98 in Helsinki on Friday.

As P.& G. and Kimberly have fought back with price cuts of their own, worried investors have hammered Drypers stock to around $8 a share, from a peak of $15 last November.

With Luiz Inácio Lula da Silva of the Workers' Party opening a wide-enough lead in opinion polls to make an outright victory in the first round of voting on Oct. 6 a real possibility, investors have been hammering Brazil's stocks and bonds.

On Friday, investors hammered Nortel's shares after the company announced late on Thursday that it would report a loss in the first quarter and cut 10,000 jobs because of slower sales in the United States.

When it surfaced this fall, investors hammered Metallgesell schaft and Deutsche Bank stock - and Metallgesellschaft's new management, along with Ronaldo H. Schmitz, the Deutsche Bank director who is chairman of Metallgesellschaft's supervisory board, fired back.