The VIX exchange traded notes from

iPath

have experienced wild trading and intense emotions in the marketplace.

The funds are the

iPath S&P 500 VIX Short Term Futures ETN

(VXX) - Get Report

, which targets one- and two-month futures, and the

VIX Medium Term Futures ETN

(VXZ) - Get Report

, which focus on futures expiring in four to seven months. VIX, the CBOE Volatility Index, is a measure of market expectations using the S&P 500 Index.

There seemed to have been two uses, or potential uses, when the funds were first listed. One was to speculate on the movement of the VIX index and the other as a potential hedge for a portfolio. An unknown factor at the start was how these might trade in the real world. The nature of the futures contracts is that they represent the market's perception of where the VIX index will be at expiration. This means that, potentially, the ETNs can diverge from the underlying index. It also means that the Short Term Futures ETN should track closer to the underlying index than the Medium Term Futures ETN -- most of the time, anyway. "Most of the time" is key here because there are very few absolutes. Any decision to use these for either purpose must consider that fact.

The VIX index is often referred to as the "fear index," with the thinking being that VIX goes up when the market goes down. This may be true as a generalization but not as an absolute. Again, there are very few absolutes.

Portfolio hedging has been a popular topic as the bear market has worn on with investors trying to find a hedging device that won't surprise them and an ETF industry seemingly intent on creating more solutions all the time.

ProShares

and

Rydex

have inverse and two-times inverse funds,

Direxion

has three-times inverse funds and

IndexIQ

has listed two ETFs that purport to provide hedge-fund strategies to individual investors. The latest is a filing from a company called

FactorETF

that plans to launch funds that will pit various asset classes and stock-market segments against each other to capture relative outperformance or underperformance. This space will only get larger.

The short-term fund has tracked closer to the underlying index than the medium-term fund has. Well-regarded options-market blogger Adam Warner from Daily Options noted that the VIX generally has a negative 0.66 correlation to the S&P 500, and the Short Term Futures ETN captures 40% to 50% of that effect. He notes that there are no enormous flaws in the VIX ETNs such as those that have surfaced in other exchange traded products. However, a possible obstacle could be a negative roll yield, which would occur if, in rolling to the next month's futures contract, the fund has to pay out more to buy the new month than was taken in by selling the old month. That has been a huge obstacle for oil ETFs.

One aspect of considering new investment products is they need time to prove themselves. Before I would consider using these, I would want to see whether they move up as the stock market goes down. In their short history, the stock market has been almost a one-way trade higher and VIX has gone lower. While there are no absolutes, the funds need to prove they can be a hedge in a down market. For now, the data are insufficient.

Roger Nusbaum is a portfolio manager with Your Source Financial of Phoenix, and the author of Random Roger's Big Picture Blog. Under no circumstances does the information in this column represent a recommendation to buy or sell stocks. Nusbaum appreciates your feedback;

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