Halving events have frequently been associated with increase in price of bitcoin with significant upward momentum both before and after halving. Bitcoin halving often generate increased market attention and hype. Expectation of lower supply and likely price increase may fuel positive feelings amongst investors and traders.
Even though this is true, it is not a guarantee that when the halving comes, the price of bitcoin will immediately experience a significant price increase. The position may change or over time may not have the same similarity when the next halving occurs, that is why bitcoin is considered speculative and even though the halving provides a way for price increases. In principle, we never know for sure, but previous trips may give an idea of how it works.
Lower supply and the relationship between supply and demand may make the formula the cause of the price increase even though that is just an assumption. Hype and Fomo may be able to suppress the market, which in turn will result in new and old investors starting to enter, thereby causing price spikes in line with the halving that has occurred.