As a publisher of a momentum newsletter, I stay abreast of the momentum in ETFs and mutual funds. The strongest momentum, however, is in the broker's reversal on offering leveraged ETFs to their clients. Ameriprise ( AMP) told brokers not to solicit the products while clients of Edward Jones and UBS ( UBS) can no longer purchase them. Wells Fargo ( WFC) and Morgan Stanley ( MS) Smith Barney are reviewing the products. Charles Schwab ( SCHW) doesn't solicit them and has a strongly worded warning as part of an article titled "Leveraged and Inverse ETFs: Not Right for Everyone."Yesterday I wrote about the fiduciary responsibility of brokers to their clients. Brokers advising clients are in a different position than online brokers that offer a trading platform, and companies that offer more advice, such as Schwab, have taken a bolder position on leveraged ETFs. The swift movement and growing number of brokerages reviewing, restricting or removing these products from their line-up can create a legal imperative on its own. Just as car manufacturers race to add safety features such as airbags, brokers will begin asking whether they want to face a judge having been in the minority that didn't change their policy. That other brokers believe it is their responsibility to protect their clients from leveraged ETFs shifts the internal debate from whether these should be allowed to whether they should be offered. Furthermore, as The Wall Street Journal reported in June, new financial legislation could require brokers to adhere to a higher standard and put their clients' interests ahead of their own, affecting everything from marketing to broker compensation.