diff --git a/xrpl4j-core/src/main/java/org/xrpl/xrpl4j/codec/binary/types/AmountType.java b/xrpl4j-core/src/main/java/org/xrpl/xrpl4j/codec/binary/types/AmountType.java
index d6386ac1f..29fc61968 100644
--- a/xrpl4j-core/src/main/java/org/xrpl/xrpl4j/codec/binary/types/AmountType.java
+++ b/xrpl4j-core/src/main/java/org/xrpl/xrpl4j/codec/binary/types/AmountType.java
@@ -300,13 +300,13 @@ public JsonNode toJson() {
    *
    * @return {@code true} if this AmountType is native; {@code false} otherwise.
    */
-  private boolean isNative() {
+  public boolean isNative() {
     // 1st bit in 1st byte is set to 0 for native XRP, 3rd bit is also 0.
     byte leadingByte = toBytes()[0];
     return (leadingByte & 0x80) == 0 && (leadingByte & 0x20) == 0;
   }
 
-  private boolean isMpt() {
+  public boolean isMpt() {
     // 1st bit in 1st byte is 0, and 3rd bit is 1
     byte leadingByte = toBytes()[0];
     return (leadingByte & 0x80) == 0 && (leadingByte & 0x20) != 0;
@@ -317,9 +317,9 @@ private boolean isMpt() {
    *
    * @return {@code true} if this AmountType is positive; {@code false} otherwise.
    */
-  private boolean isPositive() {
+  public boolean isPositive() {
     // 2nd bit in 1st byte is set to 1 for positive amounts
-    return (toBytes()[0] & 0x40) > 0;
+    return toHex().startsWith("00000000000000", 2) || (toBytes()[0] & 0x40) > 0;
   }
 
 }
diff --git a/xrpl4j-core/src/main/java/org/xrpl/xrpl4j/codec/binary/types/SerializedType.java b/xrpl4j-core/src/main/java/org/xrpl/xrpl4j/codec/binary/types/SerializedType.java
index 4a2358234..0d86b9a76 100644
--- a/xrpl4j-core/src/main/java/org/xrpl/xrpl4j/codec/binary/types/SerializedType.java
+++ b/xrpl4j-core/src/main/java/org/xrpl/xrpl4j/codec/binary/types/SerializedType.java
@@ -119,7 +119,9 @@ public T fromParser(BinaryParser parser, int lengthHint) {
   }
 
   /**
-   * Obtain a {@link T} using the supplied {@code node}.
+   * Obtain a {@link T} using the supplied {@code node}. Prefer using {@link #fromJson(JsonNode, FieldInstance)} over
+   * this method, as some {@link SerializedType}s require a {@link FieldInstance} to accurately serialize and
+   * deserialize.
    *
    * @param node A {@link JsonNode} to use.
    *
@@ -208,7 +210,9 @@ public byte[] toBytes() {
   }
 
   /**
-   * Convert this {@link SerializedType} to a {@link JsonNode}.
+   * Convert this {@link SerializedType} to a {@link JsonNode}. Prefer using {@link #toJson(FieldInstance)} over this
+   * method where possible, as some {@link SerializedType}s require a {@link FieldInstance} to accurately serialize and
+   * deserialize.
    *
    * @return A {@link JsonNode}.
    */
diff --git a/xrpl4j-core/src/test/java/org/xrpl/xrpl4j/codec/binary/types/BaseSerializerTypeTest.java b/xrpl4j-core/src/test/java/org/xrpl/xrpl4j/codec/binary/types/BaseSerializerTypeTest.java
index 12386ba06..6ce484063 100644
--- a/xrpl4j-core/src/test/java/org/xrpl/xrpl4j/codec/binary/types/BaseSerializerTypeTest.java
+++ b/xrpl4j-core/src/test/java/org/xrpl/xrpl4j/codec/binary/types/BaseSerializerTypeTest.java
@@ -50,12 +50,17 @@ protected static Stream<Arguments> dataDrivenFixturesForType(SerializedType seri
   @ParameterizedTest
   @MethodSource("dataDrivenFixtures")
   void fixtureTests(ValueTest fixture) throws IOException {
-    SerializedType serializedType = getType();
+    SerializedType<?> serializedType = getType();
     JsonNode value = getValue(fixture);
     if (fixture.error() != null) {
       assertThrows(Exception.class, () -> serializedType.fromJson(value));
     } else {
-      assertThat(serializedType.fromJson(value).toHex()).isEqualTo(fixture.expectedHex());
+      SerializedType<?> serialized = serializedType.fromJson(value);
+      if (fixture.type().equals("Amount")) {
+        assertThat(((AmountType) serialized).isPositive()).isEqualTo(!fixture.isNegative());
+        assertThat(((AmountType) serialized).isNative()).isEqualTo(fixture.isNative());
+      }
+      assertThat(serialized.toHex()).isEqualTo(fixture.expectedHex());
     }
   }
 
diff --git a/xrpl4j-core/src/test/resources/data-driven-tests.json b/xrpl4j-core/src/test/resources/data-driven-tests.json
index b704887d6..99260f8e5 100644
--- a/xrpl4j-core/src/test/resources/data-driven-tests.json
+++ b/xrpl4j-core/src/test/resources/data-driven-tests.json
@@ -3704,7 +3704,7 @@
       "is_native": false,
       "type": "Amount",
       "expected_hex": "20000000000000000100002403C84A0A28E0190E208E982C352BBD5006600555CF",
-      "is_negative": false
+      "is_negative": true
     },
     {
       "test_json": {
@@ -3811,7 +3811,7 @@
       "is_native": false,
       "type": "Amount",
       "expected_hex": "20000000000000000000002403C84A0A28E0190E208E982C352BBD5006600555CF",
-      "is_negative": false
+      "is_negative": true
     },
     {
       "test_json": {