A year-to-date gain of nearly 83% means the First Trust NASDAQ Clean Edge Green Energy Index Fund (NasdaqGS: QCLN) is one of the top-performing non-leveraged sector ETFs of 2013.

One look at QCLN’s 43 holdings explains why the ETF has been on a tear this year. Not only is the ETF an alternative energy play, it is a play on the right alternative energy stocks. Translation: Nearly a quarter of QCLN’s weight is allocated to solar stocks, an advantageous trait in a year when the two best non-leveraged ETFs are solar funds. [2013’s Top-10 ETFs]

QCLN has $84.8 million in assets under management, a number that could indicate investors have not only missed on the jaw-dropping gains offered by this ETF, but some have also missed QCLN’s utility on another front. Just a few months shy of its seventh anniversary, QCLN currently stands as a legitimate “Elon Musk ETF.” [Musk’s Legendary Status Boosts Small ETFs]

As of Nov. 1, QCLN’s largest holding was First Solar (NasdaqGM: FSLR), a nice advantage when considering the stock is up 29.2% in the past 90 days. First Solar is 8.3% of QCLN’s weight.

However, QCLN’s fifth- and sixth-largest holdings, respectively, are Musk’s Tesla (NasdaqGM: TSLA) and SolarCity (NasdaqGM: SCTY). The two stocks, both of which are up more than 394% year-to-date, combine for nearly 13% of QCLN’s weight. [Solar ETFs Soar Ahead of SolarCity Earnings]

That makes QCLN the premier option for ETF investors looking to grab a snippet of the Musk story. Few ETFs have large allocations to either Tesla or SolarCity. Few hold both stocks. The PowerShares WilderHill Clean Energy Portfolio (NYSEArca: PBW) does, but that ETF’s current combined allocation to those stocks is just 5%.

QCLN’s exposure to Tesla and SolarCity also means this is a big week for the ETF because Tesla reports quarterly results later today followed by SolarCity Wednesday.

First Trust NASDAQ Clean Edge Green Energy Index Fund

ETF Trends editorial team contributed to this post.