I am a long term supporter of xmr - but the market manipulation on poloniex is sick.
Always been like that long before Circle was involved, kinda disappointing.
And it's not just poloniex. Nothing is new when it comes to so called manipulation of prices by the whales and other big institutions. So the best way here is to study in order to join the waves or to hodl a great coin.
I'm mostly holding but also have a bot syphoning a little off the whales as the price grows and shrinks