There is no house edge in bitcoin investment so where would the barrier to cause us loose come from if at all we don't panic to sell out of Fomo or emergency needs? Maybe I am missing out here.
IMO, those are risks too. Pretty much why we still need to control the amount we're putting in to minimize the risk, we may need the money someday.
Every investment has its risk. I mean, at the end of the day, no can can bring up a fool proof evidence that guarantees anything. Most especially with timing stuff which is an important factor.
Though, bitcoin risk is much more smaller compared to altcoins.