The 10 Craziest ETFs of the YearThe 10 Craziest ETFs of the Year

As the ETF market matures, it has become more saturated. There are currently some 1,775 ETFs in in the U.S., from 97 providers on three exchanges, according to ETFGI. And that means more ETFs based on ever narrower, and ever more creative, slices of the market.

Take the Horizons Marijuana Life Sciences Index ETF (ticker: HMMJ), launched in April. It seeks to capitalize on the $50 billion cannabis industry.

Here are our top picks for the most creative ETFs that either launched or filed in the last year.