diff --git a/crypto/utils/unit_converter.py b/crypto/utils/unit_converter.py
index be99192..dfbdc12 100644
--- a/crypto/utils/unit_converter.py
+++ b/crypto/utils/unit_converter.py
@@ -1,25 +1,30 @@
 # import numpy as np
-from decimal import Decimal
+from decimal import Decimal, getcontext
 from typing import Union
 
+# Python's Decimal type defaults to 28 digits of precision, which is not enough
+# for blockchain math. The largest possible value (uint256) has 78 digits, so we
+# increase the precision to 78 to avoid rounding errors when working with big numbers.
+getcontext().prec = 78
+
 class UnitConverter:
     WEI_MULTIPLIER = '1'
     GWEI_MULTIPLIER = '1000000000'  # 1e9
     ARK_MULTIPLIER = '1000000000000000000'  # 1e18
 
     @staticmethod
-    def parse_units(value: Union[float, int, str, Decimal], unit='ark') -> int:
+    def parse_units(value: Union[float, int, str, Decimal], unit='ark') -> Decimal:
         value = Decimal(str(value))
 
         unit = unit.lower()
         if unit == 'wei':
-            return int((value * Decimal(UnitConverter.WEI_MULTIPLIER)).normalize())
+            return (value * Decimal(UnitConverter.WEI_MULTIPLIER)).normalize()
 
         if unit == 'gwei':
-            return int((value * Decimal(UnitConverter.GWEI_MULTIPLIER)).normalize())
+            return (value * Decimal(UnitConverter.GWEI_MULTIPLIER)).normalize()
 
         if unit == 'ark':
-            return int((value * Decimal(UnitConverter.ARK_MULTIPLIER)).normalize())
+            return (value * Decimal(UnitConverter.ARK_MULTIPLIER)).normalize()
 
         raise ValueError(f"Unsupported unit: {unit}. Supported units are 'wei', 'gwei', and 'ark'.")
 
diff --git a/tests/utils/test_unit_converter.py b/tests/utils/test_unit_converter.py
index af8e4c4..de63aee 100644
--- a/tests/utils/test_unit_converter.py
+++ b/tests/utils/test_unit_converter.py
@@ -2,41 +2,47 @@
 from decimal import Decimal
 
 def test_it_should_parse_units_into_wei():
-    assert UnitConverter.parse_units(1, 'wei') == 1
-    assert UnitConverter.parse_units(1.0, 'wei') == 1
-    assert UnitConverter.parse_units('1', 'wei') == 1
-    assert UnitConverter.parse_units('1.0', 'wei') == 1
+    assert UnitConverter.parse_units(1, 'wei') == Decimal('1')
+    assert UnitConverter.parse_units(1.0, 'wei') == Decimal('1')
+    assert UnitConverter.parse_units('1', 'wei') == Decimal('1')
+    assert UnitConverter.parse_units('1.0', 'wei') == Decimal('1')
 
-    assert UnitConverter.parse_units(Decimal(1), 'wei') == 1
-    assert UnitConverter.parse_units(Decimal(1.0), 'wei') == 1
-    assert UnitConverter.parse_units(Decimal('1'), 'wei') == 1
-    assert UnitConverter.parse_units(Decimal('1.0'), 'wei') == 1
+    assert UnitConverter.parse_units(Decimal(1), 'wei') == Decimal('1')
+    assert UnitConverter.parse_units(Decimal(1.0), 'wei') == Decimal('1')
+    assert UnitConverter.parse_units(Decimal('1'), 'wei') == Decimal('1')
+    assert UnitConverter.parse_units(Decimal('1.0'), 'wei') == Decimal('1')
+
+    assert isinstance(UnitConverter.parse_units(1, 'wei'), Decimal)
 
 def test_it_should_parse_units_into_gwei():
-    assert UnitConverter.parse_units(1, 'gwei') == 1000000000
-    assert UnitConverter.parse_units(1.0, 'gwei') == 1000000000
-    assert UnitConverter.parse_units('1', 'gwei') == 1000000000
-    assert UnitConverter.parse_units('1.0', 'gwei') == 1000000000
+    assert UnitConverter.parse_units(1, 'gwei') == Decimal('1000000000')
+    assert UnitConverter.parse_units(1.0, 'gwei') == Decimal('1000000000')
+    assert UnitConverter.parse_units('1', 'gwei') == Decimal('1000000000')
+    assert UnitConverter.parse_units('1.0', 'gwei') == Decimal('1000000000')
+
+    assert UnitConverter.parse_units(Decimal(1), 'gwei') == Decimal('1000000000')
+    assert UnitConverter.parse_units(Decimal(1.0), 'gwei') == Decimal('1000000000')
+    assert UnitConverter.parse_units(Decimal('1'), 'gwei') == Decimal('1000000000')
+    assert UnitConverter.parse_units(Decimal('1.0'), 'gwei') == Decimal('1000000000')
 
-    assert UnitConverter.parse_units(Decimal(1), 'gwei') == 1000000000
-    assert UnitConverter.parse_units(Decimal(1.0), 'gwei') == 1000000000
-    assert UnitConverter.parse_units(Decimal('1'), 'gwei') == 1000000000
-    assert UnitConverter.parse_units(Decimal('1.0'), 'gwei') == 1000000000
+    assert isinstance(UnitConverter.parse_units(1, 'gwei'), Decimal)
 
 def test_it_should_parse_units_into_ark():
-    assert UnitConverter.parse_units(1, 'ark') == 1000000000000000000
-    assert UnitConverter.parse_units(1.0, 'ark') == 1000000000000000000
-    assert UnitConverter.parse_units('1', 'ark') == 1000000000000000000
-    assert UnitConverter.parse_units('1.0', 'ark') == 1000000000000000000
+    assert UnitConverter.parse_units(1, 'ark') == Decimal('1000000000000000000')
+    assert UnitConverter.parse_units(1.0, 'ark') == Decimal('1000000000000000000')
+    assert UnitConverter.parse_units('1', 'ark') == Decimal('1000000000000000000')
+    assert UnitConverter.parse_units('1.0', 'ark') == Decimal('1000000000000000000')
 
-    assert UnitConverter.parse_units(Decimal(1), 'ark') == 1000000000000000000
-    assert UnitConverter.parse_units(Decimal(1.0), 'ark') == 1000000000000000000
-    assert UnitConverter.parse_units(Decimal('1'), 'ark') == 1000000000000000000
-    assert UnitConverter.parse_units(Decimal('1.0'), 'ark') == 1000000000000000000
+    assert UnitConverter.parse_units(Decimal(1), 'ark') == Decimal('1000000000000000000')
+    assert UnitConverter.parse_units(Decimal(1.0), 'ark') == Decimal('1000000000000000000')
+    assert UnitConverter.parse_units(Decimal('1'), 'ark') == Decimal('1000000000000000000')
+    assert UnitConverter.parse_units(Decimal('1.0'), 'ark') == Decimal('1000000000000000000')
+
+    assert isinstance(UnitConverter.parse_units(1, 'ark'), Decimal)
 
 def test_it_should_parse_decimal_units_into_ark():
-    assert UnitConverter.parse_units(0.1, 'ark') == 100000000000000000
-    assert UnitConverter.parse_units('0.1', 'ark') == 100000000000000000
+    assert UnitConverter.parse_units(0.1, 'ark') == Decimal('100000000000000000')
+    assert UnitConverter.parse_units('0.1', 'ark') == Decimal('100000000000000000')
 
 def test_it_should_format_units_from_wei():
     assert UnitConverter.format_units(1, 'wei') == 1.0
@@ -120,3 +126,13 @@ def test_it_should_convert_gwei_to_ark():
     assert UnitConverter.gwei_to_ark(Decimal('1')) == '0.000000001'
     assert UnitConverter.gwei_to_ark(Decimal('1000000000'), 'DARK') == '1 DARK'
     assert UnitConverter.gwei_to_ark(Decimal('1000000000')) == '1'
+
+def test_it_should_handle_large_token_supply():
+    large_supply = '999999999999999999999999999999999999999'
+    result = UnitConverter.format_units(large_supply, 'ark')
+    assert isinstance(result, Decimal)
+    assert result == Decimal('999999999999999999999.999999999999999999')
+
+    result = UnitConverter.parse_units(large_supply, 'wei')
+    assert isinstance(result, Decimal)
+    assert result == Decimal(large_supply)