The current bitcoin-rally pretend a heavy ride for the service providers of the industry, particularly the exchanges. Coinbase is famous for their shutdown in every single big price jump, but Poloniex did it for the first time now. In 2017, there was so much interest, most of the exchanges just stopped the new sign-ups, they were hardly overwhelmed.
Poloniex is one of the biggest exchanges, so maybe they don’t have enough robust infrastructure, or they find a serious bug in the system. But what is a shame, they are in the circles of Justin Sun, who can deliver the biggest interest in the cryptoverse, so they should handle this type of pressure.