That's too long but this is applicable to the best cryptos in the market including bitcoin and ethereum. I have the assurance with the top coins but if you're going to hold for the unknown cryptos in the market and you've just chosen them lately, you don't expect a lot from them for that long or you become lucky with them. It's hard to know since the market is very volatile and there are cryptocurrencies that we can't know what the future holds them.