(Updates to midafternoon trading, adds analyst comment) * Indexes down: Dow 1.08%, S&P 500 2.08%, Nasdaq 3.37% * Intel slides after reporting big cash burn * Crypto firms slide after reports that hackers stole $6.3 billion from Binance By Stephen Culp and Purvi Agarwal NEW YORK, Oct 30 (Reuters) - US stocks tumbled on Friday, with the Nasdaq plunging to a three-month low following disappointing quarterly results from Intel and Amazon, which amplified growing fears surrounding AI-related companies' massive spending on the nascent technology, and concerns about when or whether the cash burn will start to pay off.