diff --git a/vega_sim/api/data.py b/vega_sim/api/data.py
index a4e5ff1ca..989e48525 100644
--- a/vega_sim/api/data.py
+++ b/vega_sim/api/data.py
@@ -40,7 +40,7 @@ class MissingMarketError(Exception):
 PriceLevel = namedtuple("PriceLevel", ["price", "number_of_orders", "volume"])
 
 
-@dataclass
+@dataclass(frozen=True)
 class AccountData:
     owner: str
     balance: float
@@ -53,14 +53,14 @@ def account_id(self):
         return f"{self.owner}-{self.type}-{self.market_id}-{self.asset}"
 
 
-@dataclass
+@dataclass(frozen=True)
 class IcebergOrder:
     peak_size: float
     minimum_visible_size: float
     reserved_remaining: float
 
 
-@dataclass
+@dataclass(frozen=True)
 class Order:
     price: float
     size: float
@@ -127,20 +127,20 @@ class Order:
 )
 
 
-@dataclass
+@dataclass(frozen=True)
 class LiquidationPrice:
     open_volume_only: float
     including_buy_orders: float
     including_sell_orders: float
 
 
-@dataclass
+@dataclass(frozen=True)
 class MarginEstimate:
     best_case: MarginLevels
     worst_case: MarginLevels
 
 
-@dataclass
+@dataclass(frozen=True)
 class LiquidationEstimate:
     best_case: LiquidationPrice
     worst_case: LiquidationPrice
@@ -153,7 +153,7 @@ class DecimalSpec:
     asset_decimals: Optional[int] = None
 
 
-@dataclass
+@dataclass(frozen=True)
 class LedgerEntry:
     from_account: vega_protos.vega.AccountDetails
     to_account: vega_protos.vega.AccountDetails
@@ -162,7 +162,7 @@ class LedgerEntry:
     timestamp: int
 
 
-@dataclass
+@dataclass(frozen=True)
 class AggregatedLedgerEntry:
     timestamp: int
     quantity: float
@@ -176,19 +176,19 @@ class AggregatedLedgerEntry:
     to_account_market_id: str
 
 
-@dataclass
+@dataclass(frozen=True)
 class MarketDepth:
     buys: List[PriceLevel]
     sells: List[PriceLevel]
 
 
-@dataclass
+@dataclass(frozen=True)
 class OrdersBySide:
     bids: List[Order]
     asks: List[Order]
 
 
-@dataclass
+@dataclass(frozen=True)
 class Fee:
     maker_fee: float
     infrastructure_fee: float
diff --git a/vega_sim/local_data_cache.py b/vega_sim/local_data_cache.py
index b33beec4d..1af29813f 100644
--- a/vega_sim/local_data_cache.py
+++ b/vega_sim/local_data_cache.py
@@ -599,32 +599,37 @@ def get_trades_from_stream(
     def get_accounts_from_stream(
         self,
         market_id: Optional[str] = None,
-        asset_id: Optional[str] = None,
         party_id: Optional[str] = None,
+        asset_id: Optional[str] = None,
     ) -> List[data.AccountData]:
         """Loads accounts for either a given party, market or both from stream.
-        Must pass one or the other
 
         Args:
             market_id:
-                optional str, Restrict to trades on a specific market
+                optional str, Restrict to accounts on a specific market
             party_id:
-                optional str, Select only trades with a given id
+                optional str, Select only accounts with a given party id
+            asset_id:
+                optional str, Restrict to only accounts for a given asset
 
         Returns:
             List[AccountData], list of formatted trade objects which match the required
                 restrictions.
         """
-        if market_id is None and party_id is None:
-            raise Exception("At least one of market_id and party_id must be specified")
+
         with self.account_lock:
-            to_check_keys = set()
-            if market_id is not None:
-                to_check_keys.update(
-                    self._account_keys_for_market.get(market_id, set())
-                )
-            if party_id is not None:
-                to_check_keys.update(self._account_keys_for_party.get(party_id, set()))
+            if market_id is None and party_id is None:
+                to_check_keys = self._accounts_from_feed.keys()
+            else:
+                to_check_keys = set()
+                if market_id is not None:
+                    to_check_keys.update(
+                        self._account_keys_for_market.get(market_id, set())
+                    )
+                if party_id is not None:
+                    to_check_keys.update(
+                        self._account_keys_for_party.get(party_id, set())
+                    )
             results = []
             for key in to_check_keys:
                 acct = self._accounts_from_feed[key]
@@ -643,3 +648,17 @@ def get_accounts_from_stream(
                 results.append(acct)
 
         return results
+
+    def get_all_accounts_from_stream(
+        self,
+    ) -> List[data.AccountData]:
+        """Loads all accounts stored.
+
+        Returns:
+            List[AccountData], list of formatted account objects
+        """
+
+        with self.account_lock:
+            accts = list(self._accounts_from_feed.values())
+
+        return accts
diff --git a/vega_sim/scenario/common/agents.py b/vega_sim/scenario/common/agents.py
index cb168d5bd..93dc7d96f 100644
--- a/vega_sim/scenario/common/agents.py
+++ b/vega_sim/scenario/common/agents.py
@@ -2865,7 +2865,7 @@ def step(self, vega_state: VegaState):
                     self.seen_trades.add(trade.id)
                     market_trades.setdefault(market.id, []).append(trade)
 
-            accounts = self.vega.list_accounts()
+            accounts = self.vega.get_accounts_from_stream()
             self.states.append(
                 MarketHistoryData(
                     at_time=start_time,