Many banks choose not to work with cryptocurrency exchanges, so it can be difficult for them to deposit and convert funds.

The good news is many big banks are interested to integrate cryptos with the global banking system.

In the long run it will be highly profitable. So i would like to hold it for a longer period

I think Tether is a profitable investment. If you can hold those for a long term like 3-5 years, they can offer you a good return.

Other Cryptocurrencies profitable in long run are Monero , Xrp, Bitcoin cash and Litecoin if held for a longer period .

You can add ethereum in your list. XRP is offering airdrop on 12th December so far I know.