Poloniex are bigger market than Bittrex and many buyers with big pockets full BTC.
So some people want buy because read lasts press article on coindesk.com and bought. Maybe they not have accounts on bittrex I think.
But NAV is NAV. They can swap it 1:1 ratio so its not problem or maybe Polo make update coin soon.
I know , but that doesn't really explain the double price anyone with "Old" nav on polo would be crazy not to dump into polo wall and buy back @ bittrex at half price.
like you wrote before = Polo have NAV 1.0 an d Bittrex NAV 2.0 so nobody can buy on bittrex and send them to Poloniex to dump. And nobody have old NAV from active NAV owners. Swap was 1 month ago so anybody know this and make swap.
And more important on Poloniex are small amounts Nav coins in orderbook so 1-2 btc can make 100-200% rise price up. So its normal but not logic ofc
I am some sadly why I no keep some amount old NAV to sell it on Polo now. But nobody know that Polo is to lazy make update wallet to new.