Most Altcoins lose their value over time. They simply bleed their value away slowly (sometimes rapidly).
Take this into account when holding Alts for the medium and long term, and of course choose them carefully. What kind of Alts are recommended for the long term? Remember, this is only when there is a reason for making a trade. The projects/coins that have a higher daily trading volume and which have a widespread community behind them, with continuous development. You should follow the coin’s chart and identify low and stable periods. Such periods are likely to be a consolidation period by the whales, and when the right time comes, accompanied by a good press release of the project, the pump will start and they will sell in profit.