So I trade in Ethereum on an exchange called Kraken. You might have heard of it. If so, you might have heard it's terrible. I have my reasons for using it though, so let's put that aside for now.
One issue that has been a problem lately is the size of Kraken. Probably as a consequence to some issues with the platform it has become pretty small compared to the top 3 exchanges. Lately this has given rise to some particularly rich individuals playing around with the market. I was trading away, watching the market go up when suddenly it drops $5 and has a big old 250 Ether plug to prevent it from going up. On Bitfinex this would be nothing, but on Kraken it can really ruin your day if you want the market going in a specific direction. Volume is low after all.
So I'm cursing out my computer for the market suddenly dropping unnaturally like that, and then it happens again. Another 250 ether at another $5 lower offer. Then another. Now Kraken is trading over $20 below market average and there isn't enough people awake to react to it. It goes up slowly, but I was banking on the market going up. Now I'm waiting here concerned over if they're going to drop another bomb or if the market is going to drop overall before Kraken can recover.
Now, $20 isn't a huge deal. Ethereum is almost at 1k. But someone just dropped a bomb, selling their own ether at a greatly reduced price because ???. I can't think of any reason to go THAT far below market. A drop of $10 will likely fill your order pretty fast, and the fact that there are tiers of money blocks suggests some ill intent.
Kraken seems to really attract these types too. It's the exchange that was used to crash the market when someone decided to sell a crap-ton of ether and drop the market down to around $1. Yesterday someone dropped the market instantly by $50. I suspect there's just one or two really rich fellows of ill repute that are pushing around their money in such a way. As much as I hope they throw their money in a way that benefits me, I'd rather if they just disappear. Let the market flow naturally.