Several brokers who left recently said in interviews that they had talked to their clients before leaving and had made sure that most would follow. When a broker leaves, banks select new brokers to handle the accounts. Investors who want to follow their broker generally have to move their money on their own. And some investors, disappointed with the market this year, may choose not to follow their brokers.

One of the latest broker defections was last Friday when a group of four Merrill advisers in Westport, Conn., resigned to set up their own shop. The four had worked at Merrill since the late 1990s and managed $1 billion. Now they are trying to attract clients to their newly created firm, called the LLBH Group.

Merrill brokers were notified this Friday about Bank of America’s plans to retain them. Top earners will receive a cash grant equaling up to 100 percent of their recent annual production for Merrill, and they will be allowed to keep the money if they stay at Bank of America for seven years. The other half of brokers, though, will receive far less  ranging from 10 to 20 percent of their production, depending on their length of service and other factors. That could be about $40,000 for some advisers  not a lot by the standards of Wall Street payouts of even a year ago.

On the other hand, there might not have been any payments of this sort if Merrill had remained independent. The number of Merrill’s brokers was up in the third quarter, but its assets under management fell by $8 billion in the last two quarters, not counting market losses. That implies that the brokers are managing less money and some may be trainees, said Mr. Hintz, the analyst at Sanford C. Bernstein. There have also been net outflows of assets at Wachovia and Citigroup over the last two quarters.

Not just any broker can hang up a shingle and lure clients from a former employer. The ones leaving tend to have decades of experience and clients who will come to a company run in the broker’s name rather than a big bank’s. Their new businesses, though, may not have access to as many alternative investments for their clients.

Brokers still far outnumber independent advisers, and banks will probably remain the training ground for new brokers. There are just 10,000 to 15,000 independent advisers, fewer than Merrill’s herd alone, and those independent brokers manage about $2.4 trillion in assets, according to a Citigroup report on the industry in September.