FAIR VALUE MEASUREMENTS - Estimated fair value of Convertible Notes (Details) - Level 3 - Recurring |
Mar. 31, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Series A-1 Convertible Notes | Expected volatility | ||
| FAIR VALUE MEASUREMENTS | ||
| Debt Instrument, Measurement Input | 1.01 | 1.042 |
| Series A-1 Convertible Notes | Risk-free interest rate | ||
| FAIR VALUE MEASUREMENTS | ||
| Debt Instrument, Measurement Input | 0.037 | 0.0348 |
| Series B-1 Convertible Notes | Expected volatility | ||
| FAIR VALUE MEASUREMENTS | ||
| Debt Instrument, Measurement Input | 0.992 | 0.996 |
| Series B-1 Convertible Notes | Risk-free interest rate | ||
| FAIR VALUE MEASUREMENTS | ||
| Debt Instrument, Measurement Input | 0.0372 | 0.0347 |