Thanks for this interesting information. Although there is a lot of poloniex bashing here on steemit, we see polo so high in the ranking. The trading volume soared rapidly during the altcoin rallye in the beginning of this year. Perhaps this may be a reason for the issues. I suggest to everybody to use two crypto exchanges as mimium.
Agreed, and where possible you should keep your crypto in your own wallet, not on an exchange. Only exceptions might be the ones that get backlogs, for those you have to weigh counterparty risk vs. the risk of getting your transactions stuck when you want to sell...
Yes, the ability of fast trading and security of the funds must be balanced. So, If you use more than on exchange, the risk is divided.