Amid global growth concerns, looming Brexit issues and an unresolved trade spat with China, the U.S. market bulls are still raging. This is especially true as better-than-expected earnings have renewed confidence in the stock market. Upbeat results from Twitter Inc TWTR, Coca-Cola Co KO, United Technologies Corp UTX and Lockheed Martin Corp LMT eased fears of a profit recession.Notably, the S&P 500 Index and the Nasdaq Composite hit new all-time record closings on Apr 23. With this, the S&P 500 climbed nearly 25% from a low reached on Christmas Eve while Nasdaq is up more than 30% (read: : A Spread of Top-Ranked ETFs That Crushed the Market in Q1).Additionally, investors are feeling optimistic about the global economy given signs of improving growth in China with new measures and reforms, as well as steady albeit slowing growth in the U.S. economy. The Fed’s decision of not raising interest rates this year after seven hikes over the past two years also bolstered investors’ sentiment. Further, an oil price surge and bouts of upbeat data globally are providing strong support to the bulls.While every corner of the market is enjoying the ascent, high-beta stocks and ETFs are outperforming.Why?Beta measures the price volatility of stocks or funds relative to the overall market. It has a direct relationship to market movements. A beta of more than 1 indicates that the price tends to move higher than the broader market and is extremely volatile while a beta of less than 1 indicates that the price of the stock or fund is less volatile than the market.That said, high-beta stocks seek to capitalize on continued growth with market-beating returns. This is because when markets soar, high-beta stocks experience larger gains than the broader market counterparts and thus, outpace their rivals. However, these exhibit a higher level of volatility.Given the bullishness, investors could find the following ETFs and stocks intriguing:ETF PicksUsing our database, we have chosen top-ranked ETFs that have a Zacks Rank #1 (Strong Buy) or 2 (Buy) and AUM of at least $50 million to ensure better tradability and liquidity.SPDR S&P Biotech ETF XBIThis ETF offers exposure to the biotechnology segment of the healthcare space by tracking the S&P Biotechnology Select Industry Index (read: Biotechnology Market on a Tear: 5 ETFs in Spotlight).Zacks Rank: #2Beta: 1.83AUM: $4.2 billionExpense Ratio: 0.35%YTD Performance: 21.1%Invesco DWA Technology Momentum ETF PTFThis product follows the DWA Technology Technical Leaders Index and offers exposure to the technology stocks that are showing relative strength (momentum).Zacks Rank: #2Beta: 1.29AUM: $147.2 millionExpense Ratio: 0.60%YTD Performance: 32.4%Vanguard Russell 2000 Growth Index ETF VTWGThis fund offers exposure to the growth segment of the U.S. small-cap market by tracking the Russell 2000 Growth Index.Zacks Rank: #2Beta: 1.28AUM: $298.6 millionExpense Ratio: 0.20%YTD Performance: 20.2%First Trust Materials AlphaDEX Fund FXZThis product tracks the StrataQuant Materials Index, which is a modified equal-dollar weighted index to identify and select stocks from the Russell 1000 Index that may generate positive alpha relative to traditional passive style indices through the use of the AlphaDEX screening methodology.Zacks Rank: #2Beta: 1.26AUM: $148.5 millionExpense Ratio: 0.64%YTD Performance: 18%Invesco Russell MidCap Pure Growth ETF PXMGThis fund follows the Russell Midcap Pure Growth Index, which consists of securities with strong growth characteristics selected from the Russell Midcap Index (read: 5 Mid-Cap ETFs Scaling New Highs).Zacks Rank: #1Beta: 1.23AUM: $606.8 millionExpense Ratio: 0.39%YTD Performance: 31%Stocks PicksFor stocks, we have chosen those that have a top Zacks Rank, a VGM Score of A, and belongs to a top-ranked Zacks industry along with high beta.Ranger Energy Services Inc. RNGRIt is a provider of well service rigs and services primarily in the United States and focuses on unconventional horizontal well completion and production operations.Zacks Rank: #2Zacks Industry Rank: Top 38%Beta: 3.47Market Cap: $113.5 millionYTD Performance: 43.3%OneMain Holdings Inc. OMFThis is a consumer financial services holding company.Zacks Rank: #2Zacks Industry Rank: Top 14%Beta: 2.51Market Cap: $4.49 billionYTD Performance: 35.7%DXP Enterprises Inc. DXPEIt is a leading products and service distributor that adds value and total cost savings solutions to industrial customers throughout the United States, Canada, Mexico and Dubai. You can see the complete list of today’s Zacks #1 Rank stocks here.Zacks Rank: #1Zacks Industry Rank: Top 40%Beta: 2.48Market Cap: $771.13 millionYTD Performance: 57.5%NCR Corporation NCRThis company is a leader in omni-channel solutions, turning everyday interactions with businesses into exceptional experiences.Zacks Rank: #2Zacks Industry Rank: Top 10%Beta: 1.94Market Cap: $3.49 billionYTD Performance: 27.1%Avid Technology Inc. AVIDIt develops, markets, sells and supports a wide range of software and systems for creating and manipulating digital media content (read: 5 Top-Ranked ETFs & Stocks to Bloom in Spring).Zacks Rank: #1 Zacks Industry Rank: Top 4%Beta: 1.88Market Cap: $328 billionYTD Performance: 64.4%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 NCR Corporation (NCR): Free Stock Analysis Report Twitter, Inc. (TWTR): Free Stock Analysis Report Lockheed Martin Corporation (LMT): Free Stock Analysis Report Coca-Cola Company (The) (KO): Free Stock Analysis Report Avid Technology, Inc. (AVID): Free Stock Analysis Report United Technologies Corporation (UTX): Free Stock Analysis Report OneMain Holdings, Inc. (OMF): Free Stock Analysis Report SPDR S&P Biotech ETF (XBI): ETF Research Reports First Trust Materials AlphaDEX Fund (FXZ): ETF Research Reports Vanguard Russell 2000 Growth ETF (VTWG): ETF Research Reports Invesco DWA Technology Momentum ETF (PTF): ETF Research Reports DXP Enterprises, Inc. (DXPE): Free Stock Analysis Report Ranger Energy Services, Inc. (RNGR): Free Stock Analysis Report Invesco Russell MidCap Pure Growth ETF (PXMG): ETF Research Reports 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