Risk in general is volatility, risk specifically is security. Fluctuation isn't a hesitation to invest, bitcoin actually doesn't offer that. You can see some whales like M Saylor how he survived even with the red market conditions a few months ago. However, with specific risks, bitcoin can cause someone to lose their investment in just a few seconds.
But yeah, some investors prefer to go against the advice: "invest what you can afford to lose", because there is no small amount of money that is worthless.