Credit Suisse created the TVIX
or Daily 2X VIX Short-Term ETN. It stopped creating new shares after the ETN lost 60% of its value over a short period of time during the month of March. The SEC is also looking into trading activity after the sharp drop experienced during March and other broker-dealers have instituted warnings to investors about ETNs similar to the one Schwab has created.
The TVIX is considered a derivative and is a complex bet on market volatility. It has two to three times the volatility of the underlying market but investors tend to only see the upside possibilities and not the downside risks. Credit Suisse may become the focus of a class action lawsuit being considered by investors who have lost money.