You can get passive income from such fluctuations especially if you are trading the coin. So if there is a downward movement, some people have benefited one way or the other and likewise up movement too, people make passive income.
Apart from trading, people are now also making passive income through mining of coins through different medium like telegram
The point is that intelligence is needed in developing passive income potential and although there is no fixed guarantee, the potential can be maximized. Now for the guarantee of passive income from investment is not at all certain and we cannot expect it completely. That is why people need to spread several portfolios so that when one coin does not strengthen, they still have other coins to utilize. Price fluctuations will force us to wait for price recovery and from there we can sell certain coins to make a profit.
If we are able to mine and have sufficient tools, it will help to generate other profits and that is why we need the ability as a supporter. The more ways we can maximize, the greater the profit we will get. It should be so that we can continue to collect profits even in small ways in various aspects that exist, so that we can get passive profits.