There are no guarantees. So far it is bitcoin and a few chosen altcoins that continue to remain steady at the top. Bitcoin is of course the safest among all cryptocurrencies. Ethereum's future may not be that secure after it shifted to POS. BNB is also at risk after the sudden collapse of FTT due to the fraudulent activities of FTX, another huge exchange like Binance. And let us be clear that bitcoin is a currency, it may stabilize in the future just like the US dollar. But for now, bitcoin still has a big room for growth as there is only a low percentage of the world population that owns a portion of it.