Cryptocurrency ETFs jump as Bitcoin retakes $21K

Exchange traded funds tied to the cryptocurrency space saw gains in Friday's early action, buoyed by a surge in Bitcoin (BTC-USD), which climbed back above the $21K level.The rally included three of the industry's largest players: ProShares Bitcoin Strategy ETF (NYSEARCA:BITO), Valkyrie Bitcoin Strategy ETF (NASDAQ:BTF) and VanEck Bitcoin Strategy ETF (BATS:XBTF).Early on, BITO was +9.3%, BTF gained 9.7%, and XBTF advanced by 9.8%. The gains came as Bitcoin jumped 9.5% on Friday.BITO, BTF and XBTF move in synchrony with Bitcoin as all three funds use Bitcoin future contracts to price the underlying fund. Therefore, any moves in the crypto asset will reflect the price movements of the ETF.On the opposite end of the field is the ProShares Short Bitcoin Strategy ETF (BITI), which is lower by 9.5%. The fund represents a short Bitcoin-based investment vehicle, meaning it is designed to move in the opposite direction of Bitcoin.In Friday's late-morning action, Bitcoin traded near the $21,100 mark, its highest point since August 26.Year-to-date price action: BTC-USD -55.5%, BITO -55.1%, BTF -54.7%, XBTF -54.5%, and BITI -6.2%.Aside from Bitcoin-based ETFs, other blockchain related ETFs are also higher as they have an indirect exposure to Bitcoin. Four funds in particular are the Amplify Transformational Data Sharing ETF (BLOK) +3.6%, Bitwise Crypto Industry Innovators ETF (BITQ) +5.3%, Global X Blockchain ETF (BKCH) +6%, and the VanE...