Graham Barclay/Bloomberg News

Trying to hook a marlin-sized rebound in oil using exchange-traded funds isn’t as easy as it may look.

Many see oil as a bargain now that it’s below $50 a barrel for the first time since 2009. Bottom fishers are piling into oil-related ETFs at the fastest rate in years, and the ETFs have taken in $6 billion in the past six weeks. But so far no one is catching anything but negative returns.

If you’re tempted to join the crowd, keep two things in mind. First, you’re not directly investing in oil as a pure commodity play with these products — unless you want to store barrels of oil in your backyard.

Second, you’re entering dangerous territory. Similar value-hunting frenzies in Russia in 2014 and in gold miners in 2013 burned investors. The same thing could easily happen with oil, especially when you consider that it’s traded at $20 a barrel for long periods of time in the past. With those caveats as a backdrop, here are your ETF options.

Commodity ETFs

One way to try and profit from any rebound is to buy an ETF that holds oil future contracts. The most popular one is the United States Oil Fund LP (USO), which invests in soon-to-expire oil futures. The good news is this ETF is very sensitive to short-term movements in the price of oil. The bad news: Over the long term, this falls apart due to costs associated with managing ongoing positions in oil futures.

Since USO launched in April 2006, it has returned -71 percent, while the spot price of oil returned -26 percent. The last time oil roared back from a bottom was in 2009, when it returned 78 percent on the year. USO returned just 14 percent.

The other note of caution on USO is the way it is taxed. It holds futures contracts, and investors are taxed as if they themselves hold those futures contracts. This means a bit higher tax and a new tax form to fill out. Investors can sidestep this tax annoyance by using an exchange-traded note, such as the iPath S&P GSCI Crude Oil Total Return Index ETN (OIL). But with an ETN, you take on the credit risk of whatever company issued the note.

Even so, USO has raked in the most cash of any oil futures ETF. Since the end of this past November, $1 billion has flowed into the ETF; in 2013 it attracted $1.2 billion. All this while it lost 44 percent.

Another strategy is to use energy sector ETFs. The good news is that you won’t be dealing with derivatives or unusual tax treatment. The bad news is that many other events that have absolutely nothing to do with oil impact these stocks. Bad economic data, a geopolitical event or a Federal Reserve announcement — all can affect energy stocks regardless of the price of oil.

Investors interested in going the equity route can use the popular Energy Select Sector SPDR Fund (XLE), which tracks large-cap oil and gas companies such as Exxon Mobil Corp. (XOM) and Chevron Corp. (CVX). XLE has taken in $4.5 billion in the past year, while having a -10 percent return. When oil prices had a 77 percent run in 2009, XLE was up 22 percent.

Daring investors could look to XLE’s wild and crazy cousins, the SPDR Oil & Gas Equipment & Services ETF (XES) and the SPDR S&P Oil & Gas Exploration & Production ETF (XOP).

Both ETFs could be good bets for a short-term pop, since they hold both big and small oil companies. Throw in the fact that they both equal-weight their holdings and you have two industry ETFs with twice the volatility of XLE.

That volatility should pay off in a rebound. In the 2009 run, XES was up 67 percent and XOP was up 40 percent. On the flip side: They could hurt you more if the floor in oil turns out to have a cellar door.