Oil is on track to log in its biggest weekly gains in more than two years with U.S. crude climbing 9.5% this week and Brent advancing 7.8%. Hopes over the trade deal between the United States and China have lifted investor sentiments. Additionally, falling production and OPEC-led fresh crude output cuts have added to the strength.This is especially true as oil output from the OPEC plunged 530,000 barrels per day to 32.6 million a day, last month. This marks the sharpest pullback since January 2017. Saudi Arabia, the world’s biggest crude exporter, curtailed output by 420,000 barrels a day to 10.65 million last month from a record of above 11 million in November.Libya's production fell 110,000 barrels a day to 1 million a day as Sharara, the country's biggest oil field, has been offline since it was captured by an armed group and demonstrators demanding better government services in mid-December. Iran’s production also fell 120,000 barrels a day last month to 2.92 million a day.Meanwhile, major oil producers have agreed to curb production by 1.2 million barrels per day during the first six months of 2019 in order to tackle global supply glut and rebalance the oil market. The 15-member OPEC cartel has agreed to reduce its output by 800,000 barrels per day, while Russia and the allied producers will take off 400,000 barrels per day from the market (read: Is Fresh OPEC+ Output Cut Enough to Boost Oil & Energy ETFs?).This week’s gains followed the oil’s biggest weekly gain since December 2016. This made energy the best performing sector to start 2019.Given the rebounding fundamentals, many energy ETFs and stocks have generated handsome returns so far this year. Below we have highlighted them:Best ETFsInvesco Dynamic Oil & Gas Services ETF PXJThis product follows the Dynamic Oil Services Intellidex Index, which thoroughly evaluates companies based on a variety of investment merit criteria, including price momentum, earnings momentum, quality, management action and value (read: 4 Worst ETF Areas of Q4).Zacks Rank: #4 (Sell)AUM: $17.8 millionExpense Ratio: 0.63%YTD Return: 18.9%SPDR S&P Oil & Gas Equipment & Services ETF XESThis fund tracks the S&P Oil & Gas Equipment & Services Select Industry Index, which measures the performance of the companies engaged in the oil and gas equipment and services industry (read: Best & Worst Zones of 2018 and Their ETFs).Zacks Rank: #4AUM: $225 millionExpense Ratio: 0.35%YTD Return: 18.9%Invesco S&P SmallCap Energy ETF PSCEThis fund offers exposure to the small-cap segment of the energy sector by tracking the S&P Small Cap 600 Capped Energy Index.Zacks Rank: #4AUM: $28.4 millionExpense Ratio: 0.29%YTD Return: 18.2%VanEck Vectors Oil Services ETF OIHThis fund tracks the MVIS U.S. Listed Oil Services 25 Index, which offers exposure to the companies involved in oil services to the upstream oil sector, including oil equipment, oil services or oil drilling.Zacks Rank: #3 (Hold)AUM: $1.3 billionExpense Ratio: 0.35%YTD Return: 17.6%iShares U.S. Oil Equipment & Services ETF IEZThis ETF offers exposure to U.S. companies that provide equipment and services for oil exploration and extraction by tracking the Dow Jones U.S. Select Oil Equipment & Services Index (see: all the Energy ETFs here).Zacks Rank: #4AUM: $181.6 millionExpense Ratio: 0.43%YTD Return: 17.3%Best StocksFerrellgas Partners, L.P. FGPThis is engaged in the sale, distribution, marketing and trading of propane and other natural gas liquids.Zacks Rank: #3VGM Score: DMarket Cap: $121.4 millionYTD Return: 133.6%Ion Geophysical Corporation IOThis company is a leading provider of geophysical technology, services, and solutions for the global oil & gas industry.Zacks Rank: #3VGM Score: DMarket Cap: $140.9 millionYTD Return: 92.7%Calumet Specialty Products Partners, L.P. CLMTThis company is a leading independent producer of high-quality, specialty hydrocarbon products in North America.Zacks Rank: #3VGM Score: AMarket Cap: $289.3 millionYTD Return: 69.7%Chaparral Energy Inc. CHAPThis company is engaged in the oil and natural gas exploration and production (read: Biggest ETF Stories of 2018 Worth Watching in 2019).Zacks Rank: #3VGM Score: AMarket Cap: $380.5 millionYTD Return: 63.4%Basic Energy Services Inc. BASThis company provides a range of services to America's oil and gas producers.Zacks Rank: #4VGM Score: AMarket Cap: $162 millionYTD Return: 58.8%Bottom LineThough many of the products have an unfavorable Zacks Rank of #4, these are the winners to start the year. This suggests that the fundamentals for the energy market are extremely strong with the ability to stir up every kind of ETFs & stocks in the sector.Want key ETF info delivered straight to your inbox?Zacks’ free Fund Newsletter will brief you on top news and analysis, as well as top-performing ETFs, each week. Get it free >> Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report VANECK-OIL SVC (OIH): ETF Research Reports PWRSH-SP SC EGY (PSCE): ETF Research Reports PWRSH-DYN OIL&G (PXJ): ETF Research Reports SPDR-SP O&G EQP (XES): ETF Research Reports ISHARS-US OIL E (IEZ): ETF Research Reports Ion Geophysical Corporation (IO): Free Stock Analysis Report Ferrellgas Partners, L.P. (FGP): Free Stock Analysis Report Calumet Specialty Products Partners, L.P. (CLMT): Free Stock Analysis Report Basic Energy Services, Inc. (BAS): Free Stock Analysis Report Chaparral Energy, Inc. (CHAP): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report