There are many people who may understand how to trade but they spread several assets. So when one coin goes down they still have a chance in another coin. But this also does not necessarily give us passive income because the market talks about coins that are always fluctuating.
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