** Shares of cryptocurrency and blockchain-related companies slump, tracking losses in bitcoin

** Bitcoin , the world's biggest cryptocurrency, drops 2.9% to $70,711, on track for worst day since Oct. 1

** Crypto exchange Coinbase Global drops 10%, co missed estimates for third-quarter profit on Wednesday

** Brokerages Needham, Mizuho raise price target on COIN, while Oppenheimer and H.C. Wainwright cut PT

** Crypto miner Riot Platforms Inc down 11.6%, co's Q3 revenue of $84.8 mln misses analysts' estimates of $95.35 mln, as per data compiled by LSEG

** RIOT reports loss of 54 cents per share, bigger than 17 cent loss forecast

** Other crypto miners fall: MARA Holdings , U.S.-listed shares of Hut 8 and Bitfarms between 7.5% and 9.1%

** Bitcoin buyer Microstrategy bucks trend, up 2% in volatile trading following Q3 results; co announced $21 billion at market equity offering

** Bitcoin retreats from recent rally, driven by expectations that Republican Donald Trump — who has expressed support for crypto — will win a second term in November's elections

** iShares Bitcoin Trust falls 1.7%, iShares Ethereum Trust down 3.8%

(Reporting by Lisa Mattackal)

((lisapauline.mattackal@thomsonreuters.com))