I cannot attest to the validity of the aforementioned claims regarding spread manipulation by Coinexx. What I do know, is that, trading that kind of volume, with that kind of leverage, is /extremely/ high-risk. Anyone that is trading this way should plan for big losses from time-to-time, and they certainly should not leave their open positions unattended.
We should not be too quick to pass judgment beyond what can be proven as fact, especially as our options for foreign brokers are limited. That does not mean that we should just ignore what people say regarding their experiences, but we have to choose our battles wisely. Drawing unwanted attention by regulator groups could further-limit our options as traders, so it is important that we remain objective toward all claims without jumping to conclusions and that we examine the evidence intelligently.
In this case, the evidence and claims are questionable. The circumstances give further credence to the possibility that this was an isolated event; unfortunate, but plausible. A reasonable cause for the sudden spikes, aside from the volatility that was brought on by the news, could be as described in the response that was given by Coinexx – limited liquidity at that time.
To publicly claim spread manipulation in such a case is irresponsible and unfair, in my opinion.
That being said, we should always keep an eye out for all things, good and bad, and we should continue sharing our experiences with these brokers and documenting them so that we can all benefit.