“Banks are trading at a discount to the broad market based on book value. The BKX is trading at a price-to-tangible-book value of 1.58, compared with 6.33 for the S&P 500 Index. Furthermore, the BKX is trading at a price-to-tangible-book ratio below the January 2002 to April 2015 average of 2.23,” notes PowerShares.

Although KBWB features ample exposure to the largest U.S. money center banks, investors in the ETF would do well to listen closely to what the Federal Reserve is saying about interest rates. The reason being is that about half of the ETF’s 24 holdings are regional banks and that does not include the super-regionals held by the fund, such as Comerica (NYSE: CMA) and SunTrust (NYSE: STI). [Inside a Fast-Growing Bank ETF]

Investors like the KBWB story. When we last visited the ETF on April 30, it was home to just under $236 million in assets under management, meaning the fund has hauled in nearly a third of its AUM tally in less than seven weeks. [Time for Bank ETFs is Now]

PowerShares KBW Bank Portfolio