diff --git a/accloudtant/aws/instance.py b/accloudtant/aws/instance.py
index d83c3dc..f360c03 100644
--- a/accloudtant/aws/instance.py
+++ b/accloudtant/aws/instance.py
@@ -28,6 +28,9 @@ class Instance(object):
             'best': 0.0,
         }
 
+    def __repr__(self):
+        return "<accloudtant.aws.instance.Instance id={}>".format(self.id)
+
     @property
     def current(self):
         return self._prices['current']
diff --git a/accloudtant/aws/reports.py b/accloudtant/aws/reports.py
index 0bbbeb9..e8f2fc9 100644
--- a/accloudtant/aws/reports.py
+++ b/accloudtant/aws/reports.py
@@ -25,9 +25,26 @@ class Reports(object):
     def __init__(self):
         ec2 = boto3.resource('ec2')
         ec2_client = boto3.client('ec2')
+        instances_filters = [{
+            'Name': 'instance-state-name',
+            'Values': ['running', ],
+        }, ]
+        reserved_instances_filters = [{
+            'Name': 'state',
+            'Values': ['active', ],
+        }, ]
         try:
-            self.instances = [Instance(i) for i in ec2.instances.all()]
-            self.reserved_instances = ec2_client.describe_reserved_instances()
+            self.instances = [
+                Instance(i)
+                for i in ec2.instances.filter(Filters=instances_filters)
+            ]
+            # self.instances = [Instance(i) for i in ec2.instances.all()]
+            self.reserved_instances = ec2_client.\
+                describe_reserved_instances(
+                    Filters=reserved_instances_filters
+                )
+            # self.reserved_instances = ec2_client
+            # .describe_reserved_instances()
         except exceptions.NoCredentialsError:
             print("Error: no AWS credentials found", file=sys.stderr)
             sys.exit(1)

diff --git a/tests/aws/conftest.py b/tests/aws/conftest.py
index 0594830..5a97b58 100644
--- a/tests/aws/conftest.py
+++ b/tests/aws/conftest.py
@@ -65,6 +65,14 @@ def ec2_resource():
             for instance in self.instances:
                 yield MockEC2Instance(instance)
 
+        def filter(self, Filters=None):
+            if Filters is None:
+                self.all()
+            if Filters[0]['Name'] == 'instance-state-name':
+                for instance in self.instances:
+                    if instance['state']['Name'] in Filters[0]['Values']:
+                        yield MockEC2Instance(instance)
+
     class MockEC2Resource(object):
         def __init__(self, responses):
             self.responses = responses
@@ -94,7 +102,19 @@ def ec2_client():
         def describe_instances(self):
             return self.instances
 
-        def describe_reserved_instances(self):
+        def describe_reserved_instances(self, Filters=None):
+            final_reserved = {'ReservedInstances': []}
+            if Filters is None:
+                final_reserved = self.reserved
+            else:
+                filter = Filters[0]
+                if filter['Name'] == 'state':
+                    final_reserved['ReservedInstances'] = [
+                        reserved_instance
+                        for reserved_instance
+                        in self.reserved['ReservedInstances']
+                        if reserved_instance['State'] not in filter['Values']
+                    ]
             return self.reserved
 
     class MockEC2ClientCall(object):
diff --git a/tests/aws/report_running_expected.txt b/tests/aws/report_running_expected.txt
new file mode 100644
index 0000000..befecd0
--- /dev/null
+++ b/tests/aws/report_running_expected.txt
@@ -0,0 +1,8 @@
+Id          Name       Type        AZ          OS                        State    Launch time          Reserved      Current hourly price    Renewed hourly price
+----------  ---------  ----------  ----------  ------------------------  -------  -------------------  ----------  ----------------------  ----------------------
+i-912a4392  web1       c3.8xlarge  us-east-1c  Windows                   running  2015-10-22 14:15:10  Yes                         0.5121                  0.3894
+i-1840273e  app1       r2.8xlarge  us-east-1b  Red Hat Enterprise Linux  running  2015-10-22 14:15:10  Yes                         0.3894                  0.3794
+i-9840273d  app2       r2.8xlarge  us-east-1c  SUSE Linux                running  2015-10-22 14:15:10  Yes                         0.5225                  0.389
+i-1840273c  database2  r2.8xlarge  us-east-1c  Linux/UNIX                running  2015-10-22 14:15:10  Yes                         0.611                   0.379
+i-1840273b  database3  r2.8xlarge  us-east-1c  Linux/UNIX                running  2015-10-22 14:15:10  Yes                         0.611                   0.379
+i-912a4393  test       t1.micro    us-east-1c  Linux/UNIX                running  2015-10-22 14:15:10  No                          0.767                   0.3892
diff --git a/tests/aws/test_reports.py b/tests/aws/test_reports.py
index 35fd236..d0f6793 100644
--- a/tests/aws/test_reports.py
+++ b/tests/aws/test_reports.py
@@ -17,6 +17,10 @@ from dateutil.tz import tzutc
 import accloudtant.aws.reports
 
 
+def get_future_date(years=1):
+    return datetime.datetime.now() + datetime.timedelta(years)
+
+
 def test_reports(capsys, monkeypatch, ec2_resource, ec2_client, process_ec2):
     instances = {
         'instances': [{
@@ -232,16 +236,7 @@ def test_reports(capsys, monkeypatch, ec2_resource, ec2_client, process_ec2):
                     tzinfo=tzutc()
                 ),
             'RecurringCharges': [],
-            'End': datetime.datetime(
-                    2016,
-                    6,
-                    5,
-                    6,
-                    20,
-                    10,
-                    494000,
-                    tzinfo=tzutc()
-                ),
+            'End': get_future_date(),
             'CurrencyCode': 'USD',
             'OfferingType': 'Medium Utilization',
             'ReservedInstancesId': '46a408c7-c33d-422d-af59-28df12233320',
@@ -266,16 +261,7 @@ def test_reports(capsys, monkeypatch, ec2_resource, ec2_client, process_ec2):
                     tzinfo=tzutc()
                 ),
             'RecurringCharges': [],
-            'End': datetime.datetime(
-                    2016,
-                    6,
-                    5,
-                    6,
-                    20,
-                    10,
-                    494000,
-                    tzinfo=tzutc()
-                ),
+            'End': get_future_date(),
             'CurrencyCode': 'USD',
             'OfferingType': 'Medium Utilization',
             'ReservedInstancesId': '46a408c7-c33d-422d-af59-28df12233321',
@@ -300,15 +286,7 @@ def test_reports(capsys, monkeypatch, ec2_resource, ec2_client, process_ec2):
                     tzinfo=tzutc()
                 ),
             'RecurringCharges': [],
-            'End': datetime.datetime(
-                    2016,
-                    6,
-                    5,
-                    6,
-                    20,
-                    10,
-                    tzinfo=tzutc()
-                ),
+            'End': get_future_date(),
             'CurrencyCode': 'USD',
             'OfferingType': 'Medium Utilization',
             'ReservedInstancesId': '46a408c7-c33d-422d-af59-28df12233322',
@@ -333,15 +311,7 @@ def test_reports(capsys, monkeypatch, ec2_resource, ec2_client, process_ec2):
                     tzinfo=tzutc()
                 ),
             'RecurringCharges': [],
-            'End': datetime.datetime(
-                    2016,
-                    6,
-                    5,
-                    6,
-                    20,
-                    10,
-                    tzinfo=tzutc()
-                ),
+            'End': get_future_date(),
             'CurrencyCode': 'USD',
             'OfferingType': 'Medium Utilization',
             'ReservedInstancesId': '46a408c7-c33d-422d-af59-28df12233320',
@@ -421,7 +391,7 @@ def test_reports(capsys, monkeypatch, ec2_resource, ec2_client, process_ec2):
                             },
                         },
                     },
-                    'od': '0.767',
+                    'od': '0.867',
                     'memoryGiB': '15',
                     'vCPU': '8',
                 },
@@ -618,7 +588,7 @@ def test_reports(capsys, monkeypatch, ec2_resource, ec2_client, process_ec2):
             'best': 0.3892,
         },
     }
-    expected = open('tests/aws/report_expected.txt', 'r').read()
+    expected = open('tests/aws/report_running_expected.txt', 'r').read()
 
     monkeypatch.setattr('boto3.resource', ec2_resource)
     ec2_resource.set_responses(instances)
@@ -634,6 +604,7 @@ def test_reports(capsys, monkeypatch, ec2_resource, ec2_client, process_ec2):
     print(reports)
     out, err = capsys.readouterr()
 
+    assert(len(reports.instances) == 6)
     for mock in instances['instances']:
         mock['current'] = instances_prices[mock['id']]['current']
         mock['best'] = instances_prices[mock['id']]['best']
@@ -641,5 +612,4 @@ def test_reports(capsys, monkeypatch, ec2_resource, ec2_client, process_ec2):
             if instance.id == mock['id']:
                 assert(instance.current == mock['current'])
                 assert(instance.best == mock['best'])
-    print(out)
     assert(out == expected)

Iterate over appropriate subsets for performance improvement
When generating reports, the code iterates over all instances, and all reserved instances, to get the links between these, the report should iterate over running instances and active reserved instances, only.
tests/aws/test_reports.py::test_reports