A bull run is a period of time where prices are increasing. It has been long happening since bitcoin reached $70k back during summer. I have seen so many questions of whether this is the start of the bull run but... we have already started! Long before! Bitcoin can continue to increase and bull run will be sustained until then. Then the market will enter a bear run in which we will see a much downward movement of the prices.

As per altcoins, they have also been doing well these days already. But the peak of altcoins bull cycle will happen right after Bitcoin's so we might see more movement from them next year. Altcoin's movements do not dictate whether it is already the bull run for bitcoin or not.