Wall Street started the week on a shaky note due to a spike in U.S. COVID cases, which is a potential threat to economic reopening. The Dow Jones logged a 725-point loss last Monday, marking the worst day since October. The benchmark U.S. treasury yield fell to 1.19% on Jul 19.However, investors shrugged off fears and again entered the market rally with full enthusiasm. The Dow Jones then enjoyed its strongest two-day (on Jul 20 and Jul 21) rally since March. The S&P 500 and the Nasdaq too are in fine fettle. Upbeat earnings results have probably helped the markets to bounce back.The small-cap benchmark Russell 2000 Index saw the biggest rebound with a 1.7% gain. The 10-year yield too jumped back to 1.30%. Many of the stocks that were hit the hardest on Jul 19, on concerns about the COVID-19 Delta variant, bounced back in the days that followed. Airlines and cruise companies spearheaded the revival.Against this backdrop, below we highlight a few ETFs that gained 7% or more on Jul 21.ETFs in Focus Global X Blockchain ETF BKCH – Up 9.44%The underlying Solactive Blockchain Index provides exposure to companies that are positioned to benefit from further advances in the field of blockchain technology.Vaneck Vectors Digital Transformation ETF DAPP – Up 8.25%The underlying MVIS Global Digital Assets Equity Index is a rules based, modified capitalization weighted, float adjusted index intended to give investors a means of tracking the overall performance of the global digital asset segment (read: ARK Invest Preparing to Launch Bitcoin ETF).Bitwise Crypto Industry Innovators ETF BITQ – Up 8.14%The underlying Bitwise Crypto Innovators 30 Index measures the performance of companies involved in servicing the cryptocurrency markets, including crypto mining firms, crypto mining equipment suppliers, crypto financial services companies, or other financial institutions servicing primarily crypto-related clientele. The fund charges 85 bps in fees. iPatha.B Coffee Subindex TR ETN JO – Up 7.7%The underlying Bloomberg Coffee Subindex Total Return reflects the returns that are potentially available through an unleveraged investment in the futures contracts on coffee. The fund charges 45 bps in fees.Rare Earth/Strategic Metals Vaneck ETF REMX – Up 7.2%The underlying MVIS Global Rare Earth/Strategic Metals Index tracks the overall performance of companies involved in producing, refining, and recycling of rare earth and strategic metals and minerals. The fund charges 59 bps in fees. Bitcoin, Like the Internet Itself, Could Change Everything Blockchain and cryptocurrency has sparked one of the most exciting discussion topics of a generation. Some call it the “Internet of Money” and predict it could change the way money works forever. If true, it could do to banks what Netflix did to Blockbuster and Amazon did to Sears. Experts agree we’re still in the early stages of this technology, and as it grows, it will create several investing opportunities. Zacks’ has just revealed 3 companies that can help investors capitalize on the explosive profit potential of Bitcoin and the other cryptocurrencies with significantly less volatility than buying them directly. See 3 crypto-related stocks now >>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 iPath Series B Bloomberg Coffee Subindex Total Return ETN (JO): ETF Research Reports VanEck Vectors Rare EarthStrategic Metals ETF (REMX): ETF Research Reports GLBLX BLKCHN (BKCH): ETF Research Reports VanEck Vectors Digital Transformation ETF (DAPP): ETF Research Reports Bitwise Crypto Industry Innovators ETF (BITQ): ETF Research Reports To read this article on Zacks.com click here. Zacks Investment Research