During the height of the dot-com bubble,trading volume on the Over-the-Counter Bulletin Board (OTCBB) ballooned,hitting $26.2 billion in March 2000, only to settle back once the feverbroke. Now some Wall Streeters are casting anxious glances at the OTCBB, whichis signaling that the days of run-and-gun trading may soon be back. The BulletinBoard is the Wild West of the investment world, populated by stocks that don'tmeet the requirements for listing on the Nasdaq and, to many observers, are rifewith fraud. That doesn't deter some traders. In March, $5.8 billion of shareschanged hands on the OTCBB. Although that's a fraction of the volume during thebubble years, it's triple the level of a year ago. Some Wall Street veterans are worriedthat such hyperactivity may be the harbinger of a return to the days of irrationalexuberance.