diff --git a/frontend/src/leftoverMapPlotAxisSingular.ts b/frontend/src/leftoverMapPlotAxisSingular.ts
index 7a2111c08..7f7b81b02 100644
--- a/frontend/src/leftoverMapPlotAxisSingular.ts
+++ b/frontend/src/leftoverMapPlotAxisSingular.ts
@@ -48,6 +48,12 @@ export const LEFTOVER_MAP_COMPARE_PLOT_TICK_SINGULAR_SHARE =
 export const LEFTOVER_MAP_COMPARE_AXIS_TICK_SINGULAR =
   "leftover map comparison leftover axis {axis} tick {value} σ {singular}";
 
+export const LEFTOVER_MAP_COMPARE_AXIS_TICK_SHARE =
+  "leftover map comparison leftover axis {axis} tick {value} {share}%";
+
+export const LEFTOVER_MAP_COMPARE_AXIS_TICK_SINGULAR_SHARE =
+  "leftover map comparison leftover axis {axis} tick {value} σ {singular} {share}%";
+
 export type LeftoverMapPlotAxisSingular = {
   axis_index: LeftoverMapAxis["axis_index"];
   leftover_singular_value?: LeftoverMapAxis["leftover_singular_value"] | null;
@@ -213,18 +219,32 @@ export function leftoverMapComparePlotTickAxisBadge(
   };
 }
 
-/** Project finite persisted σ onto one comparison-strip tick without inventing share evidence. */
+/** Compose persisted comparison-strip tick σ/share without deriving either field. */
 export function leftoverMapCompareAxisTickBadge(
   axisIndex: number,
   tickLabel: string,
   leftoverSingular: number | null | undefined,
+  leftoverShare?: LeftoverMapAxis["leftover_share"] | null,
 ): LeftoverMapCompareAxisBadge | null {
   const singular = formatLeftoverMapPlotAxisSingular(leftoverSingular);
-  if (singular === null) {
+  const share = formatLeftoverMapPlotAxisShare(leftoverShare);
+  if (singular === null && share === null) {
     return null;
   }
+  if (singular === null) {
+    return {
+      template: LEFTOVER_MAP_COMPARE_AXIS_TICK_SHARE,
+      values: { axis: axisIndex, value: tickLabel, share: share as string },
+    };
+  }
+  if (share === null) {
+    return {
+      template: LEFTOVER_MAP_COMPARE_AXIS_TICK_SINGULAR,
+      values: { axis: axisIndex, value: tickLabel, singular },
+    };
+  }
   return {
-    template: LEFTOVER_MAP_COMPARE_AXIS_TICK_SINGULAR,
-    values: { axis: axisIndex, value: tickLabel, singular },
+    template: LEFTOVER_MAP_COMPARE_AXIS_TICK_SINGULAR_SHARE,
+    values: { axis: axisIndex, value: tickLabel, singular, share },
   };
 }
diff --git a/tests/test_grouping_comparison_strip_tick_share_contract.py b/tests/test_grouping_comparison_strip_tick_share_contract.py
new file mode 100644
index 000000000..6aa38226c
--- /dev/null
+++ b/tests/test_grouping_comparison_strip_tick_share_contract.py
@@ -0,0 +1,29 @@
+"""Executable contract for comparison-strip axis tick share captions."""
+
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+SINGULAR_SOURCE = ROOT / "frontend" / "src" / "leftoverMapPlotAxisSingular.ts"
+
+
+def test_comparison_strip_tick_keeps_axis_share_independent_of_singular() -> None:
+    """A comparison-strip tick may name persisted share when singular evidence is absent."""
+    assert SINGULAR_SOURCE.exists(), "comparison-strip axis projection helper is missing"
+    source = SINGULAR_SOURCE.read_text(encoding="utf-8")
+
+    assert "leftoverMapCompareAxisTickBadge" in source
+    assert "leftover map comparison leftover axis {axis} tick {value} {share}%" in source
+    assert "leftover map comparison leftover axis {axis} tick {value} σ {singular} {share}%" in source
+
+
+def test_comparison_strip_tick_never_infers_share_from_singular() -> None:
+    """Share-only, singular-only, combined, and empty states remain persisted-data decisions."""
+    assert SINGULAR_SOURCE.exists(), "comparison-strip axis projection helper is missing"
+    source = SINGULAR_SOURCE.read_text(encoding="utf-8")
+
+    assert "Number.isFinite" in source
+    assert "leftover_share" in source
+    assert "formatLeftoverMapPlotAxisSingular" in source
+    assert "Math.sqrt" not in source
+    assert "Math.max" not in source
diff --git a/tests/test_grouping_comparison_strip_tick_singular_contract.py b/tests/test_grouping_comparison_strip_tick_singular_contract.py
index 75a923062..1bb5e2a69 100644
--- a/tests/test_grouping_comparison_strip_tick_singular_contract.py
+++ b/tests/test_grouping_comparison_strip_tick_singular_contract.py
@@ -17,12 +17,17 @@ def test_comparison_strip_axis_tick_keeps_persisted_singular_value_without_share
 
 
 def test_comparison_strip_axis_tick_does_not_infer_sigma_or_share() -> None:
-    """Invalid σ falls back to the comparison-axis tick and no counterpart is synthesized."""
+    """Comparison-strip ticks compose persisted σ/share without deriving either field."""
     assert SINGULAR_SOURCE.exists(), "singular-value axis helper is missing"
     source = SINGULAR_SOURCE.read_text(encoding="utf-8")
-
-    assert "formatLeftoverMapPlotAxisSingular" in source
-    assert "Number.isFinite" in source
-    assert "Math.sqrt" not in source
-    tail = source.split("leftoverMapCompareAxisTickBadge", 1)[-1][:1600]
-    assert "leftover_share" not in tail
+    helper = source.split("export function leftoverMapCompareAxisTickBadge", 1)[-1]
+
+    assert "formatLeftoverMapPlotAxisSingular" in helper
+    assert "formatLeftoverMapPlotAxisShare" in helper
+    assert "leftoverSingular" in helper
+    assert "leftoverShare" in helper
+    assert "LEFTOVER_MAP_COMPARE_AXIS_TICK_SHARE" in helper
+    assert "LEFTOVER_MAP_COMPARE_AXIS_TICK_SINGULAR_SHARE" in helper
+    assert "Math.sqrt" not in helper
+    assert "Math.max" not in helper
+    assert "Math.min" not in helper