Bitcoin led the best-performing ETFs this year By: CNBC.com News December 29, 2017 at 16:18 PM EST The research director behind one of 2017's top-performing exchange-traded funds is still betting on bitcoin and electric, self-driving cars. Read More >> Related Stocks: Ark Innovation ETF Ark Next Generation Internet ETF Bitcoin (Bitstamp) Bitcoin Composite GX Lithium & Battery Tech ETF Tesla, Inc.