As crude oil market participants are no doubt aware, prices for the fuel tend to move higher between mid-February and September. What's less well known is that between February 12 and April 22, crude oil enters a seasonal "sweet spot." During that time period, The Globe and Mail explains in a recent article, crude oil has gained an average of 9 percent over the past 30 years, achieving positive results "in 21 of those periods." On an even better note, it has gained during that period in nine of the past 10 years "for an average return of 16.87 per cent." But will 2014 treat crude oil as well as past years have? The Globe and Mail believes the answer is yes. For one thing, economic growth is poised to boost demand for the fuel. For another, colder-than-average temperatures in the Northeastern United States have been driving demand for heating oil, and that has "supported the price of the energy commodity since mid-January." Finally, the technical profile for crude oil is improving — the publication notes that it is "developing a base building pattern" between US$91.24 and $100.75 per barrel. To take advantage of crude oil's upcoming sweet spot, The Globe and Mail suggests investors take a look at the United States Oil Fund (ARCA:USO) and the Horizons NYMEX Crude Oil ETF (TSX:HUC), two exchange-traded funds (ETFs) that track crude oil. Here's an overview of what those ETFs have to offer. United States Oil Fund Managed by United States Commodity Funds, the United States Oil Fund's portfolio is made up of "listed crude oil futures contracts and other oil-related futures and may consist of forwards and swap contracts," its fact sheet states. Its purpose is to track the movement of West Texas Intermediate light, sweet crude oil.