v3.26.1
Financial investments - Summary investments measured under available-for-sale (Details)
 12 Months Ended
Dec. 31, 2025
CNY (¥)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
CNY (¥)
Dec. 31, 2025
USD ($)
Financial investments        
Fair value ¥ 142,709,383 $ 20,407,170 ¥ 406,718,669  
Additions 281,795,031 40,296,153 125,500,826  
Settlements (34,723,065) (4,965,332) (398,996,244)  
Unrealized gains (losses) accumulated in other comprehensive income 3,965,808 567,103 485,868  
Total realized gains 8,509,461 1,216,837 7,914,986  
Exchange differences (7,358,869) (1,052,305) 1,085,278  
Fair value 394,897,749 56,469,626 142,709,383  
Amortized cost 390,931,941   141,685,928 $ 55,902,523
US Treasury securities with original maturities over three months        
Financial investments        
Fair value 0 0 56,181,082  
Additions 281,795,031 40,296,153 0  
Settlements 0 0 (56,243,877)  
Unrealized gains (losses) accumulated in other comprehensive income 0 0 0  
Total realized gains 4,784,483 684,172 62,795  
Exchange differences (4,753,473) (679,738)    
Fair value 281,826,041 40,300,587 0  
Allowance for Credit Loss 0   0  
Amortized cost 281,826,041     40,300,587
Wealth management products with no fixed term        
Financial investments        
Fair value 31,023,455 4,436,295 350,537,587  
Additions 0 0 0  
Settlements (31,137,165) (4,452,555) (326,818,365)  
Unrealized gains (losses) accumulated in other comprehensive income 0 0 485,868  
Total realized gains 113,710 16,260 6,818,365  
Exchange differences 0 0    
Fair value 0 0 31,023,455  
Amortized cost 0   30,000,000 0
Fund Linked Notes        
Financial investments        
Fair value 111,685,928 15,970,875 0  
Additions 0 0 125,500,826  
Settlements (3,585,900) (512,777) (15,934,002)  
Unrealized gains (losses) accumulated in other comprehensive income 3,965,808 567,103 0  
Total realized gains 3,611,268 516,405 1,033,826  
Exchange differences (2,605,396) (372,567) 1,085,278  
Fair value 113,071,708 $ 16,169,039 111,685,928  
Allowance for Credit Loss 0   0  
Amortized cost ¥ 109,105,900   ¥ 111,685,928 $ 15,601,936