Wall Street: The Wild One

In a week that left even Wall Street professionals bemused and confused, the stock market bobbed down, up, down like a Yo-Yo—and to as little apparent purpose. When the hectic action ended, the Dow-Jones industrial index stood nearly six points above its level at the beginning of the week—but more than 50 points below its level in mid-March.

Leading the pack in both directions was International Business Machines, the glamour blue chip that some Wall Streeters claim is "not a stock but a religion." IBM opened the week with a spectacular 31½...