Tumbling oil prices have tripped up a slew of predictable victims among exchange traded funds, including solar funds.

On Monday, the Guggenheim Solar ETF (NYSEArca: TAN) fell 5.2%, making the largest solar ETF the fifth-worst non-leveraged ETF on the day. That after TAN tumbled 5% last Friday. The rival Market Vectors Solar Energy ETF (NYSEArca: KWT) was barely better with a Monday loss of 4.6%.

Underscoring the solar sector’s sensitivity to oil prices (solar stocks and ETFs often perform better when oil prices rise), TAN is now lower on a year-to-date basis, though the ETF’s 3.7% 2014 loss is not nearly as startling as the 25.5% plunge notched by the United States Oil Fund (NYSEArca: USO). [A Brutal Coming for Oil ETFs]

“Analysts in recent years have debated whether alternative energy stocks are directly correlated to the price of crude oil. Some contend that pricier oil pushes renewable energy companies higher, as investors and consumers search for cheaper alternatives to fossil fuels,” reports Michael Perrault for Investor’s Business Daily.

However, the declines for KWT and TAN since peaking in early March on stunning. Since peaking on March 6, TAN and KWT are each down nearly 33%, declines that outpace the loss suffered by USO by almost 500 basis points over the same period.

It was not supposed to be this way in 2014 for solar ETFs. TAN more than doubled last year, making it not only the year’s best energy ETF, but also the best non-leveraged ETF of any stripe. From the start of 2014 through March 6, TAN surged nearly 43%.