You mentioned Siacoin, i'm holding a small amount. I'd noticed that Crypopia is now for days in mainentance state with Siacoin. Currently it's not reliable but i don't know what are exactly the reasons for that

support wrote:

SC is currently in maintenance due to investigating transaction broadcast issues.
Deposit and withdrawals will be enabled when the maintenance has been completed and the wallet is online again. There is no ETA on when the SC wallet will be back online. You can keep an eye on the SC wallet here :

https://www.cryptopia.co.nz/CoinInfo/?coin=SC

Sorry for any inconvenience this may have caused.
Please feel free to contact us if you have any further questions.
I will close this ticket.