** Shares of cryptocurrency and blockchain-related companies rise as bitcoin gains
** Bitcoin , the world's biggest cryptocurrency, up 1.2% at $68,445, climbing on rising expectations that former President Donald Trump will regain the White House in November
** Trump's gains in recent Reuters/Ipsos polls show a tight race between him and Democratic opponent Kamala Harris
** Trump has positioned himself as an advocate of crypto and the recent gains in assets like bitcoin echo the so-called Trump trades
** Ether rises 1.7% to $2,530
** Crypto exchange Coinbase Global up 3.1%, and U.S.-listed shares of blockchain farm operator Bitfarms up 4.2% premarket
** Crypto miners advance: Riot Platforms up 2.4%, Mara Holdings , formerly Marathon Digital, up 2.4%, Hut 8 up 3%, Bit Digital up 4.8%
** Shares of notable BTC buyer MicroStrategy jump 3.4%
** ProShares Bitcoin Strategy ETF up 2.8% and iShares Bitcoin Trust ETF gains 2.7%
(Reporting by Sukriti Gupta in Bengaluru)