If you want to invest for long-term use the official wallet to stack your coins...
The exchange markets not recommended for staking your coins to invest.. Although #Poloniex and #Bittrex are good exchange markets but i don't read the future.. May be these sites in the future will be hack from someone professional or DDOS attacking...

- Choose the right coin for long-term investing...
- Use the official wallet for staking...
- Keep your eyes on the price of #Bitcoin every single day...