diff --git a/.changeset/fix-min-max-multiplicity.md b/.changeset/fix-min-max-multiplicity.md
new file mode 100644
index 0000000..ee24463
--- /dev/null
+++ b/.changeset/fix-min-max-multiplicity.md
@@ -0,0 +1,6 @@
+---
+'@electric-sql/d2ts': patch
+'@electric-sql/d2mini': patch
+---
+
+fix min and max groupBy aggregates to ignore retracted values (negative multiplicity)
diff --git a/packages/d2mini/src/operators/groupBy.ts b/packages/d2mini/src/operators/groupBy.ts
index 172b66e..cf229b2 100644
--- a/packages/d2mini/src/operators/groupBy.ts
+++ b/packages/d2mini/src/operators/groupBy.ts
@@ -217,9 +217,14 @@ export function min<T>(
   return {
     preMap: (data: T) => valueExtractor(data),
     reduce: (values: [number, number][]) => {
+      const net = new Map<number, number>()
+      for (const [value, multiplicity] of values) {
+        net.set(value, (net.get(value) || 0) + multiplicity)
+      }
+
       let minValue = Number.POSITIVE_INFINITY
-      for (const [value, _multiplicity] of values) {
-        if (value < minValue) {
+      for (const [value, multiplicity] of net) {
+        if (multiplicity > 0 && value < minValue) {
           minValue = value
         }
       }
@@ -238,9 +243,14 @@ export function max<T>(
   return {
     preMap: (data: T) => valueExtractor(data),
     reduce: (values: [number, number][]) => {
+      const net = new Map<number, number>()
+      for (const [value, multiplicity] of values) {
+        net.set(value, (net.get(value) || 0) + multiplicity)
+      }
+
       let maxValue = Number.NEGATIVE_INFINITY
-      for (const [value, _multiplicity] of values) {
-        if (value > maxValue) {
+      for (const [value, multiplicity] of net) {
+        if (multiplicity > 0 && value > maxValue) {
           maxValue = value
         }
       }
diff --git a/packages/d2mini/tests/operators/groupBy.test.ts b/packages/d2mini/tests/operators/groupBy.test.ts
index 5911597..d22fcff 100644
--- a/packages/d2mini/tests/operators/groupBy.test.ts
+++ b/packages/d2mini/tests/operators/groupBy.test.ts
@@ -511,6 +511,89 @@ describe('Operators', () => {
       ]
 
       expect(latestMessage.getInner()).toEqual(expectedResult)
+
+      // --- Add a new record ---
+      input.sendData(
+        new MultiSet([
+          [{ category: 'A', amount: 25 }, 1],
+          [{ category: 'C', amount: 50 }, 1],
+        ]),
+      )
+      graph.run()
+
+      const expectedAddResult = [
+        [
+          [
+            '{"category":"A"}',
+            {
+              category: 'A',
+              minimum: 5,
+              maximum: 20,
+            },
+          ],
+          -1,
+        ],
+        [
+          [
+            '{"category":"A"}',
+            {
+              category: 'A',
+              minimum: 5,
+              maximum: 25,
+            },
+          ],
+          1,
+        ],
+        [
+          [
+            '{"category":"C"}',
+            {
+              category: 'C',
+              minimum: 50,
+              maximum: 50,
+            },
+          ],
+          1,
+        ],
+      ]
+
+      expect(latestMessage.getInner()).toEqual(expectedAddResult)
+
+      // --- Delete the current min and max ---
+      input.sendData(
+        new MultiSet([
+          [{ category: 'A', amount: 5 }, -1],
+          [{ category: 'A', amount: 25 }, -1],
+        ]),
+      )
+      graph.run()
+
+      const expectedDeleteResult = [
+        [
+          [
+            '{"category":"A"}',
+            {
+              category: 'A',
+              minimum: 5,
+              maximum: 25,
+            },
+          ],
+          -1,
+        ],
+        [
+          [
+            '{"category":"A"}',
+            {
+              category: 'A',
+              minimum: 10,
+              maximum: 20,
+            },
+          ],
+          1,
+        ],
+      ]
+
+      expect(latestMessage.getInner()).toEqual(expectedDeleteResult)
     })
 
     test('with median and mode aggregates', () => {
diff --git a/packages/d2ts/src/operators/groupBy.ts b/packages/d2ts/src/operators/groupBy.ts
index b36bbbe..c839198 100644
--- a/packages/d2ts/src/operators/groupBy.ts
+++ b/packages/d2ts/src/operators/groupBy.ts
@@ -206,9 +206,14 @@ export function min<T>(
   return {
     preMap: (data: T) => valueExtractor(data),
     reduce: (values: [number, number][]) => {
+      const net = new Map<number, number>()
+      for (const [value, multiplicity] of values) {
+        net.set(value, (net.get(value) || 0) + multiplicity)
+      }
+
       let minValue = Number.POSITIVE_INFINITY
-      for (const [value, _multiplicity] of values) {
-        if (value < minValue) {
+      for (const [value, multiplicity] of net) {
+        if (multiplicity > 0 && value < minValue) {
           minValue = value
         }
       }
@@ -227,9 +232,14 @@ export function max<T>(
   return {
     preMap: (data: T) => valueExtractor(data),
     reduce: (values: [number, number][]) => {
+      const net = new Map<number, number>()
+      for (const [value, multiplicity] of values) {
+        net.set(value, (net.get(value) || 0) + multiplicity)
+      }
+
       let maxValue = Number.NEGATIVE_INFINITY
-      for (const [value, _multiplicity] of values) {
-        if (value > maxValue) {
+      for (const [value, multiplicity] of net) {
+        if (multiplicity > 0 && value > maxValue) {
           maxValue = value
         }
       }
diff --git a/packages/d2ts/tests/operators-sqlite/groupBy.test.ts b/packages/d2ts/tests/operators-sqlite/groupBy.test.ts
index 9ab448b..af02fbf 100644
--- a/packages/d2ts/tests/operators-sqlite/groupBy.test.ts
+++ b/packages/d2ts/tests/operators-sqlite/groupBy.test.ts
@@ -512,6 +512,93 @@ describe('SQLite Operators', () => {
       ]
 
       expect(latestMessage.collection.getInner()).toEqual(expectedResult)
+
+      // --- Add a new record ---
+      input.sendData(
+        v([3, 0]),
+        new MultiSet([
+          [{ category: 'A', amount: 25 }, 1],
+          [{ category: 'C', amount: 50 }, 1],
+        ]),
+      )
+      input.sendFrontier(new Antichain([v([4, 0])]))
+      graph.run()
+
+      const expectedAddResult = [
+        [
+          [
+            '{"category":"A"}',
+            {
+              category: 'A',
+              minimum: 5,
+              maximum: 25,
+            },
+          ],
+          1,
+        ],
+        [
+          [
+            '{"category":"A"}',
+            {
+              category: 'A',
+              minimum: 5,
+              maximum: 20,
+            },
+          ],
+          -1,
+        ],
+        [
+          [
+            '{"category":"C"}',
+            {
+              category: 'C',
+              minimum: 50,
+              maximum: 50,
+            },
+          ],
+          1,
+        ],
+      ]
+
+      expect(latestMessage.collection.getInner()).toEqual(expectedAddResult)
+
+      // --- Delete the current min and max ---
+      input.sendData(
+        v([5, 0]),
+        new MultiSet([
+          [{ category: 'A', amount: 5 }, -1],
+          [{ category: 'A', amount: 25 }, -1],
+        ]),
+      )
+      input.sendFrontier(new Antichain([v([6, 0])]))
+      graph.run()
+
+      const expectedDeleteResult = [
+        [
+          [
+            '{"category":"A"}',
+            {
+              category: 'A',
+              minimum: 10,
+              maximum: 20,
+            },
+          ],
+          1,
+        ],
+        [
+          [
+            '{"category":"A"}',
+            {
+              category: 'A',
+              minimum: 5,
+              maximum: 25,
+            },
+          ],
+          -1,
+        ],
+      ]
+
+      expect(latestMessage.collection.getInner()).toEqual(expectedDeleteResult)
     })
 
     test('with median and mode aggregates', () => {
diff --git a/packages/d2ts/tests/operators/groupBy.test.ts b/packages/d2ts/tests/operators/groupBy.test.ts
index 13a86e2..d5e44bf 100644
--- a/packages/d2ts/tests/operators/groupBy.test.ts
+++ b/packages/d2ts/tests/operators/groupBy.test.ts
@@ -486,6 +486,93 @@ describe('Operators', () => {
       ]
 
       expect(latestMessage.collection.getInner()).toEqual(expectedResult)
+
+      // --- Add a new record ---
+      input.sendData(
+        v([3, 0]),
+        new MultiSet([
+          [{ category: 'A', amount: 25 }, 1],
+          [{ category: 'C', amount: 50 }, 1],
+        ]),
+      )
+      input.sendFrontier(new Antichain([v([4, 0])]))
+      graph.run()
+
+      const expectedAddResult = [
+        [
+          [
+            '{"category":"A"}',
+            {
+              category: 'A',
+              minimum: 5,
+              maximum: 25,
+            },
+          ],
+          1,
+        ],
+        [
+          [
+            '{"category":"A"}',
+            {
+              category: 'A',
+              minimum: 5,
+              maximum: 20,
+            },
+          ],
+          -1,
+        ],
+        [
+          [
+            '{"category":"C"}',
+            {
+              category: 'C',
+              minimum: 50,
+              maximum: 50,
+            },
+          ],
+          1,
+        ],
+      ]
+
+      expect(latestMessage.collection.getInner()).toEqual(expectedAddResult)
+
+      // --- Delete the current min and max ---
+      input.sendData(
+        v([5, 0]),
+        new MultiSet([
+          [{ category: 'A', amount: 5 }, -1],
+          [{ category: 'A', amount: 25 }, -1],
+        ]),
+      )
+      input.sendFrontier(new Antichain([v([6, 0])]))
+      graph.run()
+
+      const expectedDeleteResult = [
+        [
+          [
+            '{"category":"A"}',
+            {
+              category: 'A',
+              minimum: 10,
+              maximum: 20,
+            },
+          ],
+          1,
+        ],
+        [
+          [
+            '{"category":"A"}',
+            {
+              category: 'A',
+              minimum: 5,
+              maximum: 25,
+            },
+          ],
+          -1,
+        ],
+      ]
+
+      expect(latestMessage.collection.getInner()).toEqual(expectedDeleteResult)
     })
 
     test('with median and mode aggregates', () => {