Ethereum (CRYPTO: ETH) plunged more than 15% on Monday, which Benzinga pointed out was likely to happen on Saturday if the crypto lost the $1,500 level as support. News late Sunday night that crypto trading platform Celsius had decided to halt withdrawals, swaps and transfers between accounts, spooked investors who likely began to liquidate positions across similar exchanges out of fear more platforms may follow suit, contributing to the overall sector decline.