diff --git a/apps/api/src/models/rule.ts b/apps/api/src/models/rule.ts
index 9c27e0018..622375b5b 100644
--- a/apps/api/src/models/rule.ts
+++ b/apps/api/src/models/rule.ts
@@ -57,7 +57,7 @@ export abstract class Rule<T extends RuleSettings> implements RuleInterface<T> {
             previousValue +
             this.exchangeRateDataService.toCurrency(
               new Big(currentValue.quantity)
-                .mul(currentValue.marketPrice)
+                .mul(currentValue.marketPrice ?? 0)
                 .toNumber(),
               currentValue.currency,
               baseCurrency