Bitcoin price after halving cycles
When a block is mined roughly every 10 minutes, the miners collect a block reward. At the moment, the block reward is 6.25 BTC.
Every 210,000 blocks, or roughly every 4 years, an event known as the halving occurs: the block reward gets cut in half. The last halving occured on May 11th, 2020, meaning that miners before were able to get a block reward of 12.5 BTC.
As miners typically sell at least part of their mined Bitcoin (e.g., to cover their equipment and maintenance cost), the supply of new Bitcoins traded on the market decreases. At the same time, the demand for Bitcoin has increased in the past. Following the halving events, a supply shock typically occurs in the months after, driving the price of Bitcoin to much higher levels than seen before.
Additionally, we can also look at the time after the first Bitcoin block on January 3rd 2009. This event was not a halving, but the genesis of the first block, when the initial block reward was set to 50 Bitcoin.