I just saw on Coinmarketcap, the price of Btc has reached above $40k. A bull market is an opportunity for investors to take profit or wait for the risk of loss. Bull markets also often influence the emotions of market players, especially fomo. If you predict that the BTC price will be much higher, you can buy and hold to make a significant profit, but if you predict that the Bitcoin price will fall before the halving, then you can take profit and buy BTC at a lower price.