Stock-trading volume has been setting new records with regularity in recent years, but nothing so overwhelming as the current surge of trading has ever before hit Wall Street. Caught in a growing backlog of paper work, most brokerage offices have been unable to process and deliver stock certificates as fast as they have been bought and sold. Last week the nation's leading securities markets decided to curtail their hours to enable clerical staffs to catch up, just as they did for nine market days last August.
Starting this week and continuing for an indefinite period, trading will end at 2...