I think all market movements are manipulations by whales. Bitcoin is relatively not yet mainstream and normal people trading few bitcoins cannot possible move the market in huge swings.
I made most of my fortune in crypto by hodling bitcoin for about 5 years now. Last year I started to actively trade and that has also given me good results so far.
Anything is possible in the cryptocurrency space. But I feel it is unlikely that another crypto will take over BTC as it already has a firm footing. Billions of dollars are invested in bitcoins and the big boys will simply not let their investments turn to dust.
Been hodling for about 5 years and the money I have today I won't be able to save in 10 years. So hodling has proven to be a good long-term strategy for me.