The key here is to hold the right coins: for example Ethereum since ICO or Darkcoin/Dash since it first went live. Also Monero. How about Doge? Now that's the wrong coin to hold.
Doge is death coin with no developer since they leave the coin without any development ao what to expect from this? Nothing. Dont invest to it.
Choose the rght one is the first ey to win in the long term holding but how can we make sure to choose the right one? Its difficult and its only include in lucky.