When both Noah Blockchain and ERC20 NOAHP are listed on BTCNEXT, how will the trading (buying or selling) happen from now on?
When NOAHP is transferred from Noah Wallet or any Ethereum-based wallet to BTCNEXT, NOAHP becomes a universal (multi-purpose) coin and can be used both as a Noah Blockchain coin and an ERC-20 based coin. Therefore when trading, there is no difference between NOAHP and ERC-20 NOAHP - the trading happens with a universal coin.
That is why if you transfer 10k of Noah Blockchain NOAHP and 30k of ERC-20 NOAHP to BTCNEXT, you will have 40k of the universal NOAH coin on your BTCNEXT account. So you can withdraw up to 40k coins to Noah Wallet as Noah -Blockchain NOAHP or you can withdraw up to 40k coins to any Ethereum-based wallet as ERC-20 NOAHP.