Cryptocrash: Bitcoin Tumbles To Pre Korea-Missile-Launch Level After Topping $5000

Shortly after topping $5,000 (according to several exchanges), Bitcoin began to tumble dramatically - now down almost $500 - erasing all the post-North-Korea missile anxiety gains.
Ethereum has crashed even more.
In fact, 9 of the 10 largest cryptocurrencies are all plunging this morning...
While there is no specific catalyst for this drop, two events have been cited: in the US, regulators have begun officially cracking down on ICOs.