Ethereum crashed from $319 to 10c on GDAX after ‘multimillion dollar’ trade
exactly the same thing happened to me with Litecoin on GDAX.They sold off my entire holdings for $0.01  - $0 after fees. At the time LTC was trading for something like $25/LTC.It took about 3 weeks to get anything but an automated response from their support team.This was the response:"After further review, this sell was due to a margin call of your margin position on the LTC/BTC order book. A series of large sell orders were placed on the LTC/BTC order book on May 21, 2017 around 1am UTC causing a large price decline which triggered a margin call of your position when your maintenance margin ratio was exceeded.The trading engine and margin call functioned as designed. The large price decline was due to the relatively low liquidity on the order book at that time."They eventually refunded the coins.... but a couple of days later removed half of the refund with no explanation.  I'm out of pocket by about $1200.  I'm still waiting for a response from them on that one.