The first VIX products were ETNs that gave short-term traders exposure so they could hedge equity positions or speculate on spikes in stocks. The ETNs don't actually track the VIX index itself; they follow a basket of rolling volatility futures. As a result, there may be a noticeable disparity between futures-based VIX ETPs and the spot price of the VIX.

The number of VIX products has exploded in recent years. The two ETF options track medium term and short-term VIX futures: the ProShares VIX Short-Term Futures (VIXY) and the ProShares VIX Mid-Term Futures (VIXM).

There are also a number of ETNs investors can use to gain exposure to the VIX. These notes try to reflect the market views on short- or medium-term futures contracts on the VIX. But an investor looking into ETNs should be aware that these notes are senior, unsubordinated, unsecured debt obligations subject to the credit risk of the issuer.

VelocityShares Daily Long VIX
Short-Term ETN (VIIX)
VelocityShares Daily Long VIX Medium-Term ETN (VIIZ)
iPath S&P 500 VIX Short-Term
Futures ETN (VXX)
iPath S&P 500 VIX Mid-Term
Futures ETN (VXZ)

Inverse VIX ETN options include:

VelocityShares Daily Inverse
VIX Short-Term ETN (XIV)
VelocityShares Daily Inverse
VIX Medium-Term ETN (ZIV)
iPath Inverse January 2021 S&P 500 VIX Short-Term Futures ETN (IVO)
iPath Inverse S&P 500 VIX
Short-Term Futures ETN (XXV)

The UBS E-TRACS Daily Long-Short VIX ETN (XVIX) provides an alternative strategy that measures the return of the index by taking a 100% long position in the midterm index and a 50% short, or inverse, position in the short-term index.

Additionally, investors may play on the added exposure in leveraged ETN options through leveraged strategies:

VelocityShares Daily 2X VIX
Short-Term ETN (TVIX)
VelocityShares Daily 2X VIX
Medium-Term ETN (TVIZ)

Potential investors considering leveraged funds should also note that they are not considered long-term holdings. The leveraged funds, along with the rest of the VIX ETPs, aim to reflect the daily performance of the VIX and the funds will rebalance daily. Because of compounding effects, the funds may greatly diverge from the price movements of the underlying index.