As the Bitcoin halving event approaches, American mining companies are constantly buying new mining machines to expand their computing power, while also dealing with their old model machines. About 6,000 old Bitcoin mining machines will soon be idle and sent to a warehouse in Colorado Springs, where they will be refurbished and resold to overseas buyers who hope to profit from mining in a low-cost environment. Since electricity is the biggest expense in Bitcoin mining, mining companies, including listed companies Marathon Digital Holdings Inc. and Riot Platforms Inc., need to reduce their usage costs to maintain positive profits. In theory, the computing power of old mining machines may still bring profits after the halving, but it is unlikely to be realized in the case of high electricity costs in the United States. According to Ethan Vera, the Chief Operating Officer of Luxor, a cryptocurrency mining service and logistics provider, about 600,000 S19 series mining machines (most of the machines currently in use) are being transferred from the United States to Africa and South America. Some buyers will wait until after the halving to purchase second-hand mining machines, as they believe that the price will drop further at that time. Data shows that in March 2022, the selling price of second-hand S19 model mining machines was about $7,030. One year later, with the decline in the price of Bitcoin, the price of second-hand S19 machines plummeted to about $900. With the upgrade of mining machines, the price of second-hand S19 has dropped to about $427 this month, and it is expected to be sold for about $356 after the halving in May. In addition, some American miners choose not to sell their hardware, but only transfer their equipment to areas with lower electricity costs and third-party data centers.