Most of the time we regret buying something when we see the price drop. Then we don't have any more dollars to buy. But if we divide our total dollars into three or four parts and buy slowly at each down, then the chances of profit are high. And if we get profit after buying first, then we will sell. For this reason, I think it is better to invest little by little instead of investing all the dollars at once. What is your opinion?
OP, what you are talking about is called DCA strategy. If you buy using DCA method, you can buy at the average price, so if the price goes down, you will not regret it. If you have a budget of $1000, you can invest $100 on a weekly basis, but it is a personal matter. Those who plan for the long term consider DCA strategy effective. All investors, big and small, use DCA strategy, like MSTR company is doing DCA regularly. Now you should not apply DCA strategy to altcoins or shitcoins, because it may not be effective, always use DCA strategy to buy Bitcoin.