diff --git a/src/driftpy/clearing_house_user.py b/src/driftpy/clearing_house_user.py
index e545dbdf..5b16af25 100644
--- a/src/driftpy/clearing_house_user.py
+++ b/src/driftpy/clearing_house_user.py
@@ -54,18 +54,18 @@ async def get_user_account(self):
 
     async def get_user_positions_account(self) -> UserPositions:
         user_account = self.get_user_account()
-        positions = cast(
+        positions_account = cast(
             UserPositions,
             await self.clearing_house.program.account["UserPositions"].fetch(
                 user_account.positions
             ),
         )
 
-        return positions
+        return positions_account
 
     async def get_user_position(self, market_index) -> MarketPosition:
-        positions = await self.get_user_positions_account()
-        for position in positions:
+        positions_account = await self.get_user_positions_account()
+        for position in positions_account.positions:
             if position.market_index == market_index:
                 return position
         return MarketPosition(
@@ -73,10 +73,10 @@ async def get_user_position(self, market_index) -> MarketPosition:
         )
 
     async def get_unrealised_pnl(self, market_index=None):
-        positions = await self.get_user_positions_account()
+        positions_account = await self.get_user_positions_account()
 
         pnl = 0
-        for position in positions:
+        for position in positions_account.positions:
             if market_index is not None and position.market_index == market_index:
                 market = self.clearing_house.get_market(
                     position.market_index
@@ -90,9 +90,9 @@ async def get_total_collateral(self):
         return collateral + self.get_unrealised_pnl()
 
     async def get_total_position_value(self):
-        positions = await self.get_user_positions_account()
+        positions_account = await self.get_user_positions_account()
         value = 0
-        for position in positions:
+        for position in positions_account.positions:
             market = self.clearing_house.get_market(
                 position.market_index
             )  # todo repeat querying
@@ -101,9 +101,9 @@ async def get_total_position_value(self):
         return value
 
     async def get_position_value(self, market_index=None):
-        positions = await self.get_user_positions_account()
+        positions_account = await self.get_user_positions_account()
         value = 0
-        for position in positions:
+        for position in positions_account.positions:
             if market_index is not None and position.market_index == market_index:
                 market = self.clearing_house.get_market(
                     position.market_index
diff --git a/src/driftpy/math/amm.py b/src/driftpy/math/amm.py
index 2d435c66..1397ea0d 100644
--- a/src/driftpy/math/amm.py
+++ b/src/driftpy/math/amm.py
@@ -1,5 +1,16 @@
 from driftpy.constants.numeric_constants import MARK_PRICE_PRECISION, PEG_PRECISION
-from driftpy.types import SwapDirection, AssetType, PositionDirection
+from driftpy.types import PositionDirection
+from sumtypes import constructor  # type: ignore
+
+
+class SwapDirection:
+    ADD = constructor()
+    REMOVE = constructor()
+
+
+class AssetType:
+    QUOTE = constructor()
+    BASE = constructor()
 
 
 def calculate_price(base_asset_amount, quote_asset_amount, peg_multiplier):
@@ -9,14 +20,19 @@ def calculate_price(base_asset_amount, quote_asset_amount, peg_multiplier):
         return (quote_asset_amount * peg_multiplier / PEG_PRECISION) / base_asset_amount
 
 
-def calculate_swap_output(input_asset_reserve, swap_amount, invariant):
-    new_input_asset_reserve = input_asset_reserve + swap_amount
+def calculate_swap_output(
+    input_asset_reserve, swap_amount, swap_direction: SwapDirection, invariant
+):
+    if swap_direction == SwapDirection.ADD:
+        new_input_asset_reserve = input_asset_reserve + swap_amount
+    else:
+        new_input_asset_reserve = input_asset_reserve - swap_amount
     new_output_asset_reserve = invariant / new_input_asset_reserve
     return [new_input_asset_reserve, new_output_asset_reserve]
 
 
 def calculate_amm_reserves_after_swap(
-    amm, input_asset_type: AssetType, swap_amount, swap_direction: PositionDirection
+    amm, input_asset_type: AssetType, swap_amount, swap_direction: SwapDirection
 ):
 
     if input_asset_type == AssetType.QUOTE:
@@ -31,6 +47,7 @@ def calculate_amm_reserves_after_swap(
         [new_quote_asset_reserve, new_base_asset_reserve] = calculate_swap_output(
             amm.quote_asset_reserve / MARK_PRICE_PRECISION,
             swap_amount,
+            swap_direction,
             (amm.sqrt_k / MARK_PRICE_PRECISION) ** 2,
         )
 
@@ -41,6 +58,7 @@ def calculate_amm_reserves_after_swap(
         [new_base_asset_reserve, new_quote_asset_reserve] = calculate_swap_output(
             amm.base_asset_reserve / MARK_PRICE_PRECISION,
             swap_amount,
+            swap_direction,
             (amm.sqrt_k / MARK_PRICE_PRECISION) ** 2,
         )
 
diff --git a/src/driftpy/math/positions.py b/src/driftpy/math/positions.py
index f9f2625b..debf480e 100644
--- a/src/driftpy/math/positions.py
+++ b/src/driftpy/math/positions.py
@@ -27,6 +27,8 @@
     AMM_TIMES_PEG_TO_QUOTE_PRECISION_RATIO,
 )
 
+from driftpy.math.amm import AssetType
+
 
 def calculate_base_asset_value(market: Market, user_position: MarketPosition) -> int:
 
@@ -41,9 +43,9 @@ def calculate_base_asset_value(market: Market, user_position: MarketPosition) ->
 
     new_quote_asset_reserve, _ = calculate_amm_reserves_after_swap(
         market.amm,
-        "base",
+        AssetType.BASE,
         abs(user_position.base_asset_amount),
-        get_swap_direction("base", direction_to_close),
+        get_swap_direction(AssetType.BASE, direction_to_close),
     )
 
     result = None
@@ -65,7 +67,7 @@ def calculate_base_asset_value(market: Market, user_position: MarketPosition) ->
 def calculate_position_pnl(
     market: Market, market_position: MarketPosition, with_funding=False
 ):
-    pnl = 0
+    pnl = 0.0
 
     if market_position.base_asset_amount == 0:
         return pnl
@@ -79,13 +81,13 @@ def calculate_position_pnl(
 
     if with_funding:
         funding_rate_pnl = 0.0
-        pnl += funding_rate_pnl / PRICE_TO_QUOTE_PRECISION
+        pnl += funding_rate_pnl / float(PRICE_TO_QUOTE_PRECISION)
 
     return pnl
 
 
 def calculate_position_funding_pnl(market: Market, market_position: MarketPosition):
-    funding_pnl = 0
+    funding_pnl = 0.0
 
     if market_position.base_asset_amount == 0:
         return funding_pnl
@@ -100,7 +102,7 @@ def calculate_position_funding_pnl(market: Market, market_position: MarketPositi
         market_position.last_cumulative_funding_rate - amm_cum_funding_rate
     ) * market_position.base_asset_amount
 
-    funding_pnl /= int(AMM_RESERVE_PRECISION * FUNDING_PRECISION)
+    funding_pnl /= float(AMM_RESERVE_PRECISION * FUNDING_PRECISION)
 
     return funding_pnl
 
diff --git a/src/driftpy/math/trade.py b/src/driftpy/math/trade.py
index b9cd61a0..4e809ff7 100644
--- a/src/driftpy/math/trade.py
+++ b/src/driftpy/math/trade.py
@@ -2,7 +2,7 @@
 from driftpy.math.amm import calculate_price, calculate_amm_reserves_after_swap
 from driftpy.math.market import calculate_mark_price
 
-from driftpy.constants import (
+from driftpy.constants.numeric_constants import (
     MARK_PRICE_PRECISION,
     PEG_PRECISION,
     FUNDING_PRECISION,