diff --git a/src/app/(dashboard)/dashboard/costs/quota-share/QuotaSharePageClient.tsx b/src/app/(dashboard)/dashboard/costs/quota-share/QuotaSharePageClient.tsx
index 97e2e3ba63..e5d9069b07 100644
--- a/src/app/(dashboard)/dashboard/costs/quota-share/QuotaSharePageClient.tsx
+++ b/src/app/(dashboard)/dashboard/costs/quota-share/QuotaSharePageClient.tsx
@@ -142,7 +142,7 @@ export default function QuotaSharePageClient() {
 
   // ── Group state ───────────────────────────────────────────────────────────
   const [groups, setGroups] = useState<QuotaGroup[]>([]);
-  const [selectedGroupId, setSelectedGroupId] = useState<string>("group-demo");
+  const [selectedGroupId, setSelectedGroupId] = useState<string>("all");
   const [newGroupInput, setNewGroupInput] = useState("");
   const [showNewGroupInput, setShowNewGroupInput] = useState(false);
   const [renaming, setRenaming] = useState(false);
@@ -286,12 +286,24 @@ export default function QuotaSharePageClient() {
     [pools, aggregate]
   );
 
-  // Pools filtered by selected group
+  // Pools filtered by selected group (kept for stats/empty-state checks)
   const filteredPools = useMemo(
-    () => pools.filter((p) => (p as unknown as { groupId?: string }).groupId === selectedGroupId || (!( p as unknown as { groupId?: string }).groupId && selectedGroupId === "group-demo")),
+    () =>
+      selectedGroupId === "all"
+        ? pools
+        : pools.filter(
+            (p) =>
+              ((p as unknown as { groupId?: string }).groupId ?? "group-demo") === selectedGroupId
+          ),
     [pools, selectedGroupId]
   );
 
+  // Groups to render as stacked sections
+  const groupsToRender = useMemo(
+    () => (selectedGroupId === "all" ? groups : groups.filter((g) => g.id === selectedGroupId)),
+    [groups, selectedGroupId]
+  );
+
   // ── Mutations ─────────────────────────────────────────────────────────────
 
   const handleSaveAllocations = useCallback(
@@ -348,6 +360,7 @@ export default function QuotaSharePageClient() {
           title={t("groupSelectHint")}
           className="px-2 py-1 rounded border border-border bg-bg-base text-sm text-text-main min-w-[120px]"
         >
+          <option value="all">{t("allGroups")}</option>
           {groups.map((g) => (
             <option key={g.id} value={g.id}>
               {g.name}
@@ -394,7 +407,7 @@ export default function QuotaSharePageClient() {
             {t("newGroup")}
           </button>
         )}
-        {selectedGroupId !== "group-demo" && (
+        {selectedGroupId !== "all" && (
           <button
             type="button"
             onClick={() => void handleRenameGroup()}
@@ -443,19 +456,7 @@ export default function QuotaSharePageClient() {
         </div>
       ) : (
         <>
-          {/* Group heading */}
-          {groups.find((g) => g.id === selectedGroupId) && (
-            <div className="flex items-center gap-2">
-              <span className="material-symbols-outlined text-[16px] text-text-muted">folder</span>
-              <span className="text-sm font-semibold text-text-main">
-                {groups.find((g) => g.id === selectedGroupId)?.name}
-              </span>
-              <span className="text-[11px] text-text-muted">
-                ({filteredPools.length})
-              </span>
-            </div>
-          )}
-          {filteredPools.length === 0 ? (
+          {groupsToRender.length === 0 ? (
             <div className="rounded-xl border border-dashed border-border bg-surface py-10 text-center">
               <p className="text-sm text-text-muted">{t("emptyDescription")}</p>
               <Button variant="primary" size="sm" className="mt-3" onClick={() => setCreateOpen(true)}>
@@ -464,21 +465,58 @@ export default function QuotaSharePageClient() {
               </Button>
             </div>
           ) : (
-            <div className="grid grid-cols-1 lg:grid-cols-2 gap-3">
-              {filteredPools.map((pool) => (
-                <PoolCardWithUsage
-                  key={pool.id}
-                  pool={pool}
-                  keyLabels={keyLabels}
-                  connectionLabel={connLabel(pool.connectionId)}
-                  provider={connProvider(pool.connectionId)}
-                  providers={[...new Set((pool.connectionIds ?? [pool.connectionId]).map(connProvider))]}
-                  connectionIds={pool.connectionIds ?? [pool.connectionId]}
-                  onEdit={() => setEditing(pool)}
-                  onRemove={() => void handleRemovePool(pool.id)}
-                />
-              ))}
-            </div>
+            groupsToRender.map((g) => {
+              const groupPools = pools.filter(
+                (p) =>
+                  ((p as unknown as { groupId?: string }).groupId ?? "group-demo") === g.id
+              );
+              return (
+                <div key={g.id} className="flex flex-col gap-3">
+                  {/* Per-group heading */}
+                  <div className="flex items-center gap-2">
+                    <span className="material-symbols-outlined text-[16px] text-text-muted">
+                      folder
+                    </span>
+                    <span className="text-sm font-semibold text-text-main">{g.name}</span>
+                    <span className="text-[11px] text-text-muted">({groupPools.length})</span>
+                  </div>
+                  {groupPools.length === 0 ? (
+                    <div className="rounded-xl border border-dashed border-border bg-surface py-6 text-center">
+                      <p className="text-sm text-text-muted">{t("emptyDescription")}</p>
+                      <Button
+                        variant="primary"
+                        size="sm"
+                        className="mt-3"
+                        onClick={() => setCreateOpen(true)}
+                      >
+                        <span className="material-symbols-outlined text-[14px] mr-1">add</span>
+                        {t("newPool")}
+                      </Button>
+                    </div>
+                  ) : (
+                    <div className="grid grid-cols-1 md:grid-cols-2 xl:grid-cols-3 gap-3">
+                      {groupPools.map((pool) => (
+                        <PoolCardWithUsage
+                          key={pool.id}
+                          pool={pool}
+                          keyLabels={keyLabels}
+                          connectionLabel={connLabel(pool.connectionId)}
+                          provider={connProvider(pool.connectionId)}
+                          providers={[
+                            ...new Set(
+                              (pool.connectionIds ?? [pool.connectionId]).map(connProvider)
+                            ),
+                          ]}
+                          connectionIds={pool.connectionIds ?? [pool.connectionId]}
+                          onEdit={() => setEditing(pool)}
+                          onRemove={() => void handleRemovePool(pool.id)}
+                        />
+                      ))}
+                    </div>
+                  )}
+                </div>
+              );
+            })
           )}
         </>
       )}
diff --git a/src/i18n/messages/en.json b/src/i18n/messages/en.json
index 6a181a7142..b20d38a617 100644
--- a/src/i18n/messages/en.json
+++ b/src/i18n/messages/en.json
@@ -7912,7 +7912,8 @@
     "groupSelectHint": "Filter pools by group",
     "groupAllocationNote": "Allocations apply to all pools in this group via the shared quota layer.",
     "groupNamePrompt": "Enter group name",
-    "wizardGroupLabel": "Group"
+    "wizardGroupLabel": "Group",
+    "allGroups": "All groups"
   },
   "plugins": {
     "title": "Plugins",
diff --git a/src/i18n/messages/pt-BR.json b/src/i18n/messages/pt-BR.json
index 6ebd0f7e91..ed94723077 100644
--- a/src/i18n/messages/pt-BR.json
+++ b/src/i18n/messages/pt-BR.json
@@ -5417,7 +5417,8 @@
     "groupSelectHint": "Filtrar pools por grupo",
     "groupAllocationNote": "As alocações se aplicam a todos os pools deste grupo através da camada de cota compartilhada.",
     "groupNamePrompt": "Digite o nome do grupo",
-    "wizardGroupLabel": "Grupo"
+    "wizardGroupLabel": "Grupo",
+    "allGroups": "Todos os grupos"
   },
   "requestLogger": {
     "recording": "Recording",
diff --git a/tests/unit/quota-groups-ui.test.ts b/tests/unit/quota-groups-ui.test.ts
index 4b2e0d2d7b..8502b6c628 100644
--- a/tests/unit/quota-groups-ui.test.ts
+++ b/tests/unit/quota-groups-ui.test.ts
@@ -130,10 +130,12 @@ test("QuotaSharePageClient: filters pool list by selectedGroupId (filteredPools)
 });
 
 test("QuotaSharePageClient: renders group heading above pool grid", () => {
-  // The group heading shows the group name and pool count
+  // The group heading shows the group name and pool count.
+  // Task 4 replaced the single-group heading (filteredPools.length) with
+  // per-group headings using groupPools.length — one section per group.
   assert.ok(
-    pageSrc.includes("filteredPools.length"),
-    "QuotaSharePageClient must show filteredPools count in the group heading"
+    pageSrc.includes("groupPools.length") || pageSrc.includes("filteredPools.length"),
+    "QuotaSharePageClient must show pool count in the group heading (groupPools.length or filteredPools.length)"
   );
 });
 
diff --git a/tests/unit/quota-share-layout-v2.test.ts b/tests/unit/quota-share-layout-v2.test.ts
new file mode 100644
index 0000000000..6ea312f9f3
--- /dev/null
+++ b/tests/unit/quota-share-layout-v2.test.ts
@@ -0,0 +1,152 @@
+/**
+ * tests/unit/quota-share-layout-v2.test.ts
+ *
+ * Task 4 — source-level assertions for the "all groups" default,
+ * stacked group sections, and 3-column card grid in QuotaSharePageClient.
+ *
+ * Pattern mirrors tests/unit/quota-groups-ui.test.ts (source-scan).
+ * Node.js native test runner — no DOM setup required.
+ */
+
+import test from "node:test";
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import { join, dirname } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const ROOT = join(dirname(fileURLToPath(import.meta.url)), "..", "..");
+
+const PAGE_CLIENT_PATH = join(
+  ROOT,
+  "src/app/(dashboard)/dashboard/costs/quota-share/QuotaSharePageClient.tsx"
+);
+
+const EN_PATH = join(ROOT, "src/i18n/messages/en.json");
+const PT_PATH = join(ROOT, "src/i18n/messages/pt-BR.json");
+
+const pageSrc = readFileSync(PAGE_CLIENT_PATH, "utf8");
+
+// ── 1. Default state is "all" ────────────────────────────────────────────────
+
+test('QuotaSharePageClient: selectedGroupId defaults to "all"', () => {
+  assert.ok(
+    pageSrc.includes('useState<string>("all")'),
+    'QuotaSharePageClient must default selectedGroupId to "all" via useState<string>("all")'
+  );
+});
+
+// ── 2. "All groups" option in <select> ──────────────────────────────────────
+
+test('QuotaSharePageClient: <select> has an option with value="all" using t("allGroups")', () => {
+  assert.ok(
+    pageSrc.includes('value="all"'),
+    'QuotaSharePageClient <select> must include an <option value="all">'
+  );
+  assert.ok(
+    pageSrc.includes('t("allGroups")') || pageSrc.includes("t('allGroups')"),
+    'The "all" option must use the t("allGroups") i18n key'
+  );
+});
+
+// ── 3. Multi-group render (groupsToRender iteration) ─────────────────────────
+
+test("QuotaSharePageClient: renders groups by iterating groupsToRender (all-groups mode)", () => {
+  // Must derive groupsToRender (or equivalent) and map over it
+  assert.ok(
+    pageSrc.includes("groupsToRender"),
+    "QuotaSharePageClient must define groupsToRender to iterate over groups"
+  );
+  // The render must map over groupsToRender to produce per-group sections
+  assert.ok(
+    pageSrc.includes("groupsToRender.map") || pageSrc.includes("groupsToRender.filter") || pageSrc.includes(".map((g)") || pageSrc.includes(".map((g, "),
+    "QuotaSharePageClient must map over groupsToRender to render one section per group"
+  );
+});
+
+test("QuotaSharePageClient: computes groupsToRender from selectedGroupId === \"all\" check", () => {
+  // The all-groups path: selectedGroupId === "all" ? groups : groups.filter(...)
+  assert.ok(
+    pageSrc.includes('selectedGroupId === "all"'),
+    'QuotaSharePageClient must branch on selectedGroupId === "all" when computing groupsToRender'
+  );
+});
+
+// ── 4. 3-column grid ──────────────────────────────────────────────────────────
+
+test("QuotaSharePageClient: card grid uses xl:grid-cols-3", () => {
+  assert.ok(
+    pageSrc.includes("xl:grid-cols-3"),
+    "QuotaSharePageClient card grid className must include xl:grid-cols-3"
+  );
+});
+
+test("QuotaSharePageClient: card grid uses md:grid-cols-2", () => {
+  assert.ok(
+    pageSrc.includes("md:grid-cols-2"),
+    "QuotaSharePageClient card grid className must include md:grid-cols-2 (intermediate breakpoint)"
+  );
+});
+
+// ── 5. Rename button hidden/disabled when "all" is selected ──────────────────
+
+test('QuotaSharePageClient: rename button is hidden/disabled when selectedGroupId === "all"', () => {
+  // When selectedGroupId === "all", the rename button should be hidden or disabled.
+  // The old guard was `selectedGroupId !== "group-demo"`.
+  // New guard must exclude "all" (either explicit !== "all" or a more general check).
+  assert.ok(
+    pageSrc.includes('selectedGroupId !== "all"') ||
+      // guard via a truthy group lookup (groups.find(g.id === selectedGroupId) is falsy for "all")
+      pageSrc.includes("groups.find((g) => g.id === selectedGroupId)") ||
+      pageSrc.includes("groups.find(g => g.id === selectedGroupId)"),
+    'Rename button must be hidden when selectedGroupId === "all" (guard via !== "all" or group lookup)'
+  );
+});
+
+// ── 6. i18n parity: allGroups key ────────────────────────────────────────────
+
+test('i18n en.json: quotaShare.allGroups exists and equals "All groups"', () => {
+  const en = JSON.parse(readFileSync(EN_PATH, "utf8")) as Record<
+    string,
+    Record<string, string>
+  >;
+  assert.equal(
+    typeof en["quotaShare"]?.["allGroups"],
+    "string",
+    "en.json must have quotaShare.allGroups"
+  );
+  assert.equal(
+    en["quotaShare"]["allGroups"],
+    "All groups",
+    'en.json quotaShare.allGroups must equal "All groups"'
+  );
+});
+
+test('i18n pt-BR.json: quotaShare.allGroups exists and equals "Todos os grupos"', () => {
+  const pt = JSON.parse(readFileSync(PT_PATH, "utf8")) as Record<
+    string,
+    Record<string, string>
+  >;
+  assert.equal(
+    typeof pt["quotaShare"]?.["allGroups"],
+    "string",
+    "pt-BR.json must have quotaShare.allGroups"
+  );
+  assert.equal(
+    pt["quotaShare"]["allGroups"],
+    "Todos os grupos",
+    'pt-BR.json quotaShare.allGroups must equal "Todos os grupos"'
+  );
+});
+
+test("i18n parity: allGroups present in both en and pt-BR", () => {
+  const en = JSON.parse(readFileSync(EN_PATH, "utf8")) as Record<
+    string,
+    Record<string, string>
+  >;
+  const pt = JSON.parse(readFileSync(PT_PATH, "utf8")) as Record<
+    string,
+    Record<string, string>
+  >;
+  assert.ok("allGroups" in (en["quotaShare"] ?? {}), "en.json missing quotaShare.allGroups");
+  assert.ok("allGroups" in (pt["quotaShare"] ?? {}), "pt-BR.json missing quotaShare.allGroups");
+});