PowerShares Senior Loan Portfolio (NYSEArca: BKLN)
AUM as of Nov. 8: $6.13 billion
2013 growth: $4.65 billion
Comment: Investors have cozied up to senior loan ETFs as yield plays and as a defense against rising interest rates. The result is BKLN is not only the fastest growing PowerShares ETF this year, but over the past year as well. A 4.1% 30-day SEC yield helps.