March of the Broker-Dealers

The $XBD/broker-dealers steadily outperformed the SPX over the past decade, through boom, bust, panic and euphoria. Given the fact that many of the broker-dealers basically are the world's largest hedge funds (GS, LEH, etc), the $XBD has benefited from a global rise in trading and increased liquidity.

While many are forecasting a bear market, the real moment to be concerned is when the $XBD breaks down. When, if ever, will that happen?