Hey there
In june & July I bought Digibyte & Stratis & Siacoin with all my bitcoins, till now I lost almost 80%
What can I do, HOLD or Sell or What!
I think you should sell before things get worse. The altcoins are sharply lower then you should sell because it does not have a solid financial foundation. so that's going to be bad altcoin. You should focus on investing in top altcoins like ETH or XRP. That would be the profitable altcoins for you in the future.