diff --git a/content/monte-carlo-with-batch/monte-carlo-with-batch.files/stack.yaml b/content/monte-carlo-with-batch/monte-carlo-with-batch.files/stack.yaml
index e27b26bb..7314a190 100644
--- a/content/monte-carlo-with-batch/monte-carlo-with-batch.files/stack.yaml
+++ b/content/monte-carlo-with-batch/monte-carlo-with-batch.files/stack.yaml
@@ -592,7 +592,52 @@ Resources:
     Type: AWS::Lambda::Function
     Properties:
       Code:
-        ZipFile: "import json, boto3, sys\n\ndef lambda_handler(event, context):\n uri = event['inputUri']\n uri_components = uri.split('s3://')[1].split('/')\n bucket = uri_components[0]\n key = uri_components[1]\n s3 = boto3.resource('s3')\n obj = s3.Object(bucket, key)\n \n raw_data = obj.get()['Body'].read().decode('utf-8') \n json_data = json.loads(raw_data)\n array_job_size = len(json_data[\"positions\"])\n return {\n   'statusCode': 200,\n   'body': \n   {\n     'arrayJobSize': array_job_size,\n     'bucket': bucket,\n     'key': key\n   }\n }"
+        ZipFile: |
+        import json
+        import boto3
+        import sys
+
+        def lambda_handler(event, context):
+            uri = event['outputUri']  # the location that the AWS Batch result files were written to
+            uri_components = uri.split('s3://')[1].split('/')
+            bucket = uri_components[0]
+            prefix = uri_components[1]
+            
+            s3 = boto3.resource('s3')
+            result = s3.meta.client.list_objects_v2(Bucket=bucket, Prefix=prefix)    
+
+            items = result.get("Contents", [])
+            aggregation = {}  # Dictionary for aggregating by strike
+            for item in items:
+                # get handle to S3 object
+                s3key = item["Key"]
+                obj = s3.Object(bucket, s3key)
+                
+                # each file contains a single line of JSON containing the strike and PV
+                strike_pv_pair = obj.get()['Body'].read().decode('utf-8') 
+                pair = json.loads(strike_pv_pair)
+                if pair:
+                    strike = pair.get("strike")
+                    pv = pair.get("pv", "0")  # Provide a default value of "0" if "pv" is not present
+                    if strike and strike != 'null' and pv:
+                        try:
+                            pv_value = float(pv)
+                            if strike in aggregation:
+                                aggregation[strike] += pv_value
+                            else:
+                                aggregation[strike] = pv_value
+                        except ValueError:
+                            # Handle the case where pv cannot be converted to float
+                            print(f"Skipping invalid pv value: {pv} for strike: {strike}")
+
+            # upload to S3
+            obj = s3.Object(bucket, "aggregation_" + prefix + ".json")
+            obj.put(Body=(bytes(json.dumps(aggregation).encode('utf-8'))))
+
+            return {
+                'statusCode': 200,
+                'body': json.dumps(aggregation, default=str)
+            }
       Role:
         Fn::GetAtt:
           - PreprocessingServiceRole532E6474