VXX has a market cap of $1.7 billion, according to issuer Barclays.
UNG, the natural gas ETF, can also be hurt by contango because it invests in futures contracts. It has total assets of $1.1 billion.
The five-year total annualized returns for UNG were down 43.6% as of July 6, according to Morningstar. The ETF has been hammered with natural gas prices on a supply glut.
iPath S&P 500 VIX Short Term Futures ETN
U.S. Natural Gas Fund