diff --git a/src/lib/components/echarts/line-chart.tsx b/src/lib/components/echarts/line-chart.tsx
index 7fa3f0e..631a8d0 100644
--- a/src/lib/components/echarts/line-chart.tsx
+++ b/src/lib/components/echarts/line-chart.tsx
@@ -13,6 +13,7 @@ const LineChart: React.FC<ChartProps> = (props) => {
     seriesData,
     xAxisData,
     yAxisName,
+    yAxisMax,
     height,
     width,
     labelFormatter,
@@ -96,6 +97,9 @@ const LineChart: React.FC<ChartProps> = (props) => {
       return {
         ...item,
         ...lineItemConfig,
+        // a series whose data marks isolated points (per-item symbol)
+        // opts back into symbol rendering
+        showSymbol: item.showSymbol ?? lineItemConfig.showSymbol,
         smooth: smooth,
         itemStyle: {
           ...lineItemConfig.itemStyle,
@@ -132,6 +136,7 @@ const LineChart: React.FC<ChartProps> = (props) => {
       yAxis: {
         ...options.yAxis,
         name: yAxisName,
+        max: yAxisMax ?? undefined,
         nameTextStyle: {
           fontSize: 12,
           align: 'right'
@@ -147,6 +152,7 @@ const LineChart: React.FC<ChartProps> = (props) => {
     seriesData,
     xAxisData,
     yAxisName,
+    yAxisMax,
     title,
     smooth,
     titleOptions,
diff --git a/src/lib/components/echarts/types.ts b/src/lib/components/echarts/types.ts
index d393930..c130625 100644
--- a/src/lib/components/echarts/types.ts
+++ b/src/lib/components/echarts/types.ts
@@ -29,6 +29,9 @@ export interface ChartProps {
   smooth?: boolean;
   color?: string;
   yAxisName?: string;
+  // pins the y-axis ceiling (e.g. 100 for percentage charts); left
+  // unset, echarts scales the axis to the data
+  yAxisMax?: number;
   stack?: string | false;
   gaugeConfig?: {
     radius?: string;