对利润求一个ln，不然太大了看不清…… fix

strategy/src/predictor.rs

@@ -676,7 +676,11 @@ impl Predictor {
         let inventory = self.inventory;
 
         let p: Decimal = self.profit_fixed_vec.iter().sum();
-        let sigma_square = (p + Decimal::ONE).ln();
+        let sigma_square = if p > Decimal::ZERO {
+            (p + Decimal::ONE).ln()
+        } else {
+            -(p.abs() + Decimal::ONE).ln()
+        };
         // let sigma_square = self.error_rate;
 
         let gamma = self.fair_rate_focus_open;