Bitcoin slides 10% to $51K, leading cryptocurrency decline

Bitcoin drops 10% to about $51K, down 17% from its high of ~$61.2K in mid-March.The unwinding of bitcoin options contracts may be helping to drive the cryptocurrency down, according to some analysts.Investors trying to profit from their bets against bitcoin in the options market "have led to spot selling pressure into the quarter end," Shane Ai, head of research and development at crypto exchange Bybit, told Markets Insider.Ari Paul, co-founder of BlockTower Capital, sees bitcoin falling to the low $40Ks "plausible," at which point he would likely buy.Meanwhile, Ethereum dips ~8.3%, recently trading at $1,581, and Binance Coin sinks 13% to $231.38.In related news, Coinbase (COIN) is establishing a presence in India, even as India is preparing to prohibit cryptocurrency ownership."By housing some IT services, including engineering, software development and customer support operations in India, we will benefit from its huge pool of world-class engineering talent," the company said on its blog.Separately, NYDIG CEO