S&P Capital IQ also has four-star ratings on Trina Solar (NYSE: TSL) and SunPower (NasdaqGM: SPWR), which combine for 9.7% of TAN’s weight. SunEdison (NYSE: SUNE) earns a five-star rating from S&P Capital IQ. That stock is 5.7% of TAN’s weight, but not a member of KWT’s 32-stock lineup.

The research firm as a three-star rating on Elon Musk’s SolarCity (NasdaqGM: SCTY). That stock, which has more than quadrupled since its January IPO, has been a member of TAN for most of this year, but was recently added to KWT. That accounts for some of the performance gap, in TAN’s favor, between the two funds. [Solar ETFs Soar Ahead of Solar City Earnings]

S&P rates TAN and KWT underweight, but that is not necessarily a bearish call.

The two ETFs “are rated as Underweight, mainly due to their high expense ratios and negative fair value metrics associated with these vehicles, we believe they still have favorable attributes. For instance, both have a positive S&P Capital IQ STARS outlook,” said S&P in the note.

Guggenheim Solar ETF