** Shares of cryptocurrency and blockchain-related firms drop premarket, following slide in bitcoin
** Bitcoin BTC=, world's largest cryptocurrency, down 3% at $103,633.58, lowest since late June; Ether ETH= off 2.8% to $3,498.28
** U.S. stock futures tumble on Tues as major Wall Street banks warn of market pullback, dragging down risk assets .N
** Shares of crypto exchange Coinbase Global COIN.O down 3% before the bell
** BTC accumulator Strategy MSTR.O, formerly known as MicroStrategy, down >3%
** Retail trading platform Robinhood HOOD.O drops 4%
** Crypto miners down: Riot Platforms RIOT.O 4%, Mara Holdings MARA.O 2%, Hut 8 HUT.O 4%, CleanSpark CLSK.O 4%, Bit Digital BTBT.O nearly 5%
** ProShares Bitcoin Strategy ETF BITO.P and iShares Bitcoin Trust ETF IBIT.O both down >2%
(Lance Tupper is a Reuters market analyst. The views expressed are his own)
((lance.tupper@tr.com ; 1-646-279-6380))