diff --git a/frontend/src/utils/ChartManager.ts b/frontend/src/utils/ChartManager.ts
index 60a26ad..e55f5b8 100644
--- a/frontend/src/utils/ChartManager.ts
+++ b/frontend/src/utils/ChartManager.ts
@@ -740,37 +740,49 @@ export class ChartManager {
 
   /** 이중 plot 지표 — addIndicator 루프에서 누락된 plot 시리즈 추가 */
   /**
-   * OBV pane y축 스케일을 최근 N봉 실제 값 기준으로 강제 고정.
-   * 과거에 OBV가 큰 값을 기록했어도 현재 구간이 y축 하단에 압축되지 않도록 방지.
+   * OBV pane: plot0(본선)=하반부, plot1(신호선)=상반부로 scale 분리.
+   * 두 선이 언제나 pane의 서로 다른 절반에 표시되어 항상 시각적으로 구분됨.
    */
   private _applyObvTightScale(
     seriesList: ISeriesApi<SeriesType>[],
     plots: Record<string, PlotData>,
-    recentCount = 60,
+    seriesMeta?: IndicatorEntry['seriesMeta'],
   ): void {
-    const allRecent: number[] = [];
+    seriesList.forEach((s, i) => {
+      const plotId = seriesMeta?.[i]?.plotId;
+      try {
+        const ps = s.priceScale();
+        if (plotId === 'plot1') {
+          // 신호선: 상반부 (하단 55% 여백)
+          ps.applyOptions({ scaleMargins: { top: 0.03, bottom: 0.55 }, visible: false });
+        } else {
+          // 본선(plot0): 하반부 (상단 55% 여백)
+          ps.applyOptions({ scaleMargins: { top: 0.55, bottom: 0.03 } });
+        }
+      } catch { /* ok */ }
+    });
+    // plot0에 전체 값 범위 기준 autoscaleInfoProvider (과거 극값에 의한 압축 방지)
+    const allPts: number[] = [];
     for (const key of ['plot0', 'plot1']) {
       const pts = (plots[key] ?? []).filter(p => p.value != null && isFinite(p.value as number));
-      const slice = pts.slice(-recentCount).map(p => p.value as number);
-      allRecent.push(...slice);
+      allPts.push(...pts.slice(-60).map(p => p.value as number));
     }
-    if (allRecent.length === 0) return;
-    const minV = Math.min(...allRecent);
-    const maxV = Math.max(...allRecent);
-    const span = Math.max(1, maxV - minV);
-    const pad  = span * 0.3;
-    const tMin = minV - pad;
-    const tMax = maxV + pad;
-    for (const s of seriesList) {
-      try {
-        // eslint-disable-next-line @typescript-eslint/no-explicit-any
-        (s as ISeriesApi<any>).applyOptions({
-          autoscaleInfoProvider: () => ({
-            priceRange: { minValue: tMin, maxValue: tMax },
-            margins: { above: 0, below: 0 },
-          }),
-        });
-      } catch { /* ok */ }
+    if (allPts.length > 0) {
+      const minV = Math.min(...allPts);
+      const maxV = Math.max(...allPts);
+      const span = Math.max(1, maxV - minV);
+      const pad  = span * 0.15;
+      seriesList.forEach(s => {
+        try {
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
+          (s as ISeriesApi<any>).applyOptions({
+            autoscaleInfoProvider: () => ({
+              priceRange: { minValue: minV - pad, maxValue: maxV + pad },
+              margins: { above: 0, below: 0 },
+            }),
+          });
+        } catch { /* ok */ }
+      });
     }
   }
 
@@ -848,7 +860,7 @@ export class ChartManager {
         def,
       );
       if (config.type === 'OBV' && !indicatorHidden && entry.seriesList.length > 0) {
-        this._applyObvTightScale(entry.seriesList, result.plots as Record<string, PlotData>);
+        this._applyObvTightScale(entry.seriesList, result.plots as Record<string, PlotData>, entry.seriesMeta);
       }
       entry.config = config;
       if (entry.seriesList.length > 0) {
@@ -935,6 +947,11 @@ export class ChartManager {
           const fallbackColor = config.type === 'OBV' && plotDef.id === 'plot0'
             ? (regPlot?.color ?? '#2196F3')
             : (regPlot?.color ?? plotDef.color ?? '#2962FF');
+          // OBV: plot1(신호선)은 별도 priceScaleId → 상반부 / plot0(본선)은 하반부
+          const obvSignalScaleId = `obv-sig-${config.id}`;
+          const seriesPriceScaleId = (config.type === 'OBV' && plotDef.id === 'plot1')
+            ? obvSignalScaleId
+            : undefined;
           series = this.chart.addSeries(LineSeries, {
             color:            resolvePlotLineColor(plotDef.color, fallbackColor),
             lineWidth:        (config.type === 'OBV' && plotDef.id === 'plot0'
@@ -946,6 +963,7 @@ export class ChartManager {
             title:            showSeriesTitle ? this.seriesTitleForPlot(config, plotDef) : '',
             visible:          isPlotVisible,
             ...(indicatorPriceFormat ? { priceFormat: indicatorPriceFormat } : {}),
+            ...(seriesPriceScaleId ? { priceScaleId: seriesPriceScaleId } : {}),
           }, pane);
           series.setData(filtered.map(p => ({ time: p.time as Time, value: p.value })));
           seriesMeta.push({ plotId: plotDef.id, isHistogram: false, color: plotDef.color });
@@ -966,9 +984,9 @@ export class ChartManager {
         );
       }
 
-      // OBV: 최근 50봉 값 기준으로 y축 고정 → 과거 큰 값에 의한 스케일 압축 방지
+      // OBV: plot0=하반부, plot1=상반부로 분리 → 언제나 두 선이 시각적으로 구분됨
       if (config.type === 'OBV' && !indicatorHidden && seriesList.length > 0) {
-        this._applyObvTightScale(seriesList, result.plots as Record<string, PlotData>);
+        this._applyObvTightScale(seriesList, result.plots as Record<string, PlotData>, seriesMeta);
       }
 
       // hlines(과열선/중앙선/침체선)는 첫 번째 시리즈에만 한 번 생성 (중복 방지)
@@ -1086,11 +1104,11 @@ export class ChartManager {
       if (!DUAL_LINE_INDICATOR_TYPES.has(entry.type)) continue;
       await this._ensureDualLinePlotSeriesForEntry(entry);
       if (entry.config) this.applyIndicatorStyle(entry.config);
-      // OBV: tight scale 재적용 (스타일 갱신 후 autoscaleInfoProvider 덮어써질 수 있음)
+      // OBV: 분리 스케일 재적용 (스타일 갱신 후 scaleMargins 덮어써질 수 있음)
       if (entry.type === 'OBV' && entry.seriesList.length > 0 && this.rawBars.length > 0) {
         try {
           const result = await calculateIndicator('OBV', this.rawBars.slice(), entry.config?.params ?? {});
-          this._applyObvTightScale(entry.seriesList, result.plots as Record<string, PlotData>);
+          this._applyObvTightScale(entry.seriesList, result.plots as Record<string, PlotData>, entry.seriesMeta);
         } catch { /* ok */ }
       }
     }
@@ -3005,6 +3023,21 @@ export class ChartManager {
       }
     }
 
+    // OBV: 스타일 갱신 후 pane 분리 scaleMargins 재적용
+    if (entry.type === 'OBV' && entry.seriesList.length > 0) {
+      entry.seriesList.forEach((s, i) => {
+        const pid = entry.seriesMeta[i]?.plotId;
+        try {
+          const ps = s.priceScale();
+          if (pid === 'plot1') {
+            ps.applyOptions({ scaleMargins: { top: 0.03, bottom: 0.55 }, visible: false });
+          } else {
+            ps.applyOptions({ scaleMargins: { top: 0.55, bottom: 0.03 } });
+          }
+        } catch { /* ok */ }
+      });
+    }
+
     if (entry.type === 'BollingerBands') {
       detachBbBandFill(entry);
       if (this._shouldShowBbBandFillForConfig(config)) {