TVIX is the symbol for the VelocityShares 2x Long VIX Short Term Exchange note, managed by Credit Suisse Group AG. The Credit Suisse ETN is designed to track stock-market volatility. It is linked to the Chicago Board Options Exchange Volatility Index (VIX). The ETN is designed to magnify the VIX's volatility, allowing investors to make or lose twice as much as the daily move in the VIX. 
- Chaos Over a Plunging Note. The Wall Street Journal.