BTCKING555 tweeted that the Jianan Yunzhi miner with an energy efficiency ratio of 47 J / TH performed the worst. The best-selling model is the old model with energy efficiency ratio of 55/60 J / TH, which is cheaper than other mining machines. Due to the increased difficulty of mining, according to BTC.com data, the current difficulty of BTC mining has increased to 16.55T. Coupled with the drop in the price of bitcoin, Jianan Yunzhi had to sell miners at a price lower than the cost price, reducing inventory pressure, so its profit margin pressure was high. Related parties estimate that Jianan Yunzhi's net income this year is in the range of 40 million to 50 million US dollars, which is far from the net income (200 million US dollars) that they intend to achieve in the IPO report. Recently, a number of U.S. law firms initiated a class action lawsuit against Canaan Technology. At the same time, Canaan Zhizhi was shorted by Wall Street, alleging that it did not truthfully disclose related parties and fictional income through connected transactions, and allegedly forged financial status.