Yups, the Bitcoin price will not continue to be stable. It is true what he said. Because the ups and downs of a currency must have certain causes. There is no way, the price of that currency will become stable. Maybe for a few days you can, but on the next day there will definitely be something that causes the price to decrease, whether it's from an economic or political situation it can cause the Bitcoin price to either slowly decline or immediately drop far from its usual price. Vice versa, this situation can also make currency prices improve and soar up, even exceeding the usual price. The price of crypto is basically influenced by its demand and availability in the market.

As an example :

The demand for bitcoin in the market is on the rise, but the availability of sellers is not able to meet the demands of buyers in the market. Thus, the price of bitcoin goes up, because demand is higher than availability. Likewise, when the market wants to melt bitcoin into cash and its availability floods the market. Thus, the price of bitcoins will fall, as there are more sales than purchases.