Monday, April 10 was the first day of trading for a new exchange-traded fund (ETF) that tracks the price of West Texas Intermediate (WTI) crude oil. Managed by Victoria Bay Asset Management, the United States Oil Fund (AMEX:USO) uses futures contracts to mimic the price of WTI -- the crude oil benchmark most often quoted on the nightly news.

The backers of this ETF are likely hoping to follow the runaway success of the StreetTRACKSGold Trust (NYSE:GLD), which was launched in 2004. This gold ETF, along with iSharesCOMEX Gold Trust (AMEX:IAU), has created an opportunity for individual investors to participate in the gold market without needing to hold gold bullion. Likewise, the United States Oil Fund offers investors the opportunity to participate in the crude oil market without the need for a commodity futures trading account.

Black gold is not gold
The similarities end there -- both ETF vehicles offer investors the opportunity to more easily participate in a commodity market. However, there seems to be limited reason for individual investors to buy crude oil directly. Crude oil prices are volatile and may not provide a hedge against market downturns. If there is a recession, demand for crude will likely fall, and the price will almost certainly follow. Conversely, gold performs well when the economy is bad, as investors search for somewhere "safe" to put their money.

For individuals looking to benefit from increased oil prices, there are plenty of other options. There are seven integrated oil companies with market caps of $100 billion or more, and the largest of them, ExxonMobil (NYSE:XOM), has a market cap of $390 billion. There are dozens of other large-cap companies engaged in exploration and production, oil services, or refining. Beyond the individual companies, there are numerous mutual funds and ETFs that allow investors to invest in a diversified portfolio of oil-related companies.

The gold industry, however, is nowhere near the size of the oil industry. There are only five pure-play gold mining companies with market caps of $10 billion or greater, and the largest company, Newmont Mining (NYSE:NEM), has a market cap of $25 billion. Therefore, a gold ETF offers the hedging power of gold in a market where there are limited options for participation.

Final thoughts
There has been a lot of interest in the United States Oil Fund -- the ETF has traded nearly a million shares a day. However, I imagine the greater availability of investment options in the oil market will likely leave the United States Oil Fund sitting on the sidelines of most portfolios, mine included. The next time it starts to rain, I'm betting that most investors will rather own gold.

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Fool contributor Robert Aronen owns shares in both the StreetTRACKS Gold Trust and the iShares COMEX Gold Trust. He wishes he could own the bullion directly because it's shiny, but he has nowhere to hide it. Feel free to share your comments with him. The Motley Fool has a disclosure policy.