diff --git a/frontend/src/components/HistoricalChartWidget.tsx b/frontend/src/components/HistoricalChartWidget.tsx
index 567ff53..67760ae 100644
--- a/frontend/src/components/HistoricalChartWidget.tsx
+++ b/frontend/src/components/HistoricalChartWidget.tsx
@@ -2,7 +2,7 @@ import { Box, CircularProgress, Alert } from '@mui/material';
 import type { CotizacionBolsa } from '../models/mercadoModels';
 import { useApiData } from '../hooks/useApiData';
 import { LineChart, Line, XAxis, YAxis, CartesianGrid, Tooltip, Legend, ResponsiveContainer } from 'recharts';
-import { formatFullDateTime } from '../utils/formatters';
+import { formatFullDateTime, formatCurrency2Decimal } from '../utils/formatters';
 
 interface HistoricalChartWidgetProps {
     ticker: string;
@@ -10,6 +10,11 @@ interface HistoricalChartWidgetProps {
     dias: number;
 }
 
+// Formateador para el eje X que solo muestra día/mes
+const formatXAxis = (tickItem: string) => {
+    return new Date(tickItem).toLocaleDateString('es-AR', { day: '2-digit', month: '2-digit' });
+};
+
 const formatTooltipLabel = (label: string) => {
     return formatFullDateTime(label);
 };
@@ -23,16 +28,25 @@ export const HistoricalChartWidget = ({ ticker, mercado, dias }: HistoricalChart
     }
 
     if (error) {
-        return <Alert severity="error" sx={{height: 300}}>{error}</Alert>;
+        return <Alert severity="error" sx={{ height: 300 }}>{error}</Alert>;
     }
 
     if (!data || data.length < 2) {
-        return <Alert severity="info" sx={{height: 300}}>No hay suficientes datos históricos para graficar.</Alert>;
+        return <Alert severity="info" sx={{ height: 300 }}>No hay suficientes datos históricos para graficar.</Alert>;
     }
 
-    // Formateador para el eje X que solo muestra día/mes
-    const formatXAxis = (tickItem: string) => {
-        return new Date(tickItem).toLocaleDateString('es-AR', { day: '2-digit', month: '2-digit' });
+    // 1. Calcular el dominio del eje Y con un margen
+    const prices = data.map(p => p.precioActual);
+    const dataMin = Math.min(...prices);
+    const dataMax = Math.max(...prices);
+    const padding = (dataMax - dataMin) * 0.05; // 5% de padding
+    const domainMin = Math.floor(dataMin - padding);
+    const domainMax = Math.ceil(dataMax + padding);
+
+    // 2. Formateador de ticks para el eje Y más robusto
+    const yAxisTickFormatter = (tick: number) => {
+        // Usamos el formateador de moneda
+        return `$${formatCurrency2Decimal(tick)}`;
     };
 
     return (
@@ -40,13 +54,17 @@ export const HistoricalChartWidget = ({ ticker, mercado, dias }: HistoricalChart
             <LineChart data={data} margin={{ top: 5, right: 30, left: 20, bottom: 5 }}>
                 <CartesianGrid strokeDasharray="3 3" />
                 <XAxis dataKey="fechaRegistro" tickFormatter={formatXAxis} />
-                <YAxis domain={['dataMin - dataMin * 0.02', 'dataMax + dataMax * 0.02']} tickFormatter={(tick) => `$${tick.toLocaleString('es-AR')}`} />
-                <Tooltip 
-                    formatter={(value: number) => [`$${value.toFixed(2)}`, 'Precio']} 
-                    labelFormatter={formatTooltipLabel} 
+                <YAxis
+                    domain={[domainMin, domainMax]}
+                    tickFormatter={yAxisTickFormatter}
+                    width={80} // Damos un poco más de espacio para números grandes
+                />
+                <Tooltip
+                    formatter={(value: number) => [`$${formatCurrency2Decimal(value)}`, 'Precio']}
+                    labelFormatter={formatTooltipLabel}
                 />
                 <Legend />
-                <Line type="monotone" dataKey="precioActual" name="Precio de Cierre" stroke="#028fbe" strokeWidth={2} dot={false} />
+                <Line type="monotone" dataKey="precioActual" name="Precio de Cierre" stroke="#8884d8" strokeWidth={2} dot={false} />
             </LineChart>
         </ResponsiveContainer>
     );
diff --git a/frontend/src/components/MervalHeroCard.tsx b/frontend/src/components/MervalHeroCard.tsx
index dd498fb..df9b232 100644
--- a/frontend/src/components/MervalHeroCard.tsx
+++ b/frontend/src/components/MervalHeroCard.tsx
@@ -5,7 +5,7 @@ import ArrowDownwardIcon from '@mui/icons-material/ArrowDownward';
 import RemoveIcon from '@mui/icons-material/Remove';
 
 import type { CotizacionBolsa } from '../models/mercadoModels';
-import { formatInteger, formatCurrency } from '../utils/formatters';
+import { formatInteger, formatCurrency, formatCurrency2Decimal } from '../utils/formatters';
 import { HistoricalChartWidget } from './HistoricalChartWidget';
 import { useApiData } from '../hooks/useApiData';
 
@@ -53,7 +53,7 @@ export const MervalHeroCard = () => {
             <Box sx={{ display: 'flex', justifyContent: 'space-between', alignItems: 'flex-start', mb: 2 }}>
                 <Box>
                     <Typography variant="h5" component="h2" sx={{ fontWeight: 'bold' }}>Índice S&P MERVAL</Typography>
-                    <Typography variant="h3" component="p" sx={{ fontWeight: 'bold', mt:1 }}>{formatInteger(mervalData.precioActual)}</Typography>
+                    <Typography variant="h3" component="p" sx={{ fontWeight: 'bold', mt:1 }}>{formatCurrency2Decimal(mervalData.precioActual)}</Typography>
                 </Box>
                 <Box sx={{ pt: 2 }}>
                     <VariacionMerval actual={mervalData.precioActual} anterior={mervalData.cierreAnterior} />
diff --git a/frontend/src/utils/formatters.ts b/frontend/src/utils/formatters.ts
index 1103340..0dbeaa8 100644
--- a/frontend/src/utils/formatters.ts
+++ b/frontend/src/utils/formatters.ts
@@ -11,6 +11,18 @@ export const formatCurrency = (num: number, currency = 'ARS') => {
   }).format(num);
 };
 
+export const formatCurrency2Decimal = (num: number, currency = 'ARS') => {
+  const style = currency === 'USD' ? 'currency' : 'decimal';
+  const locale = currency === 'USD' ? 'en-US' : 'es-AR';
+  
+  return new Intl.NumberFormat(locale, {
+    style: style,
+    currency: currency,
+    minimumFractionDigits: 2,
+    maximumFractionDigits: 2,
+  }).format(num);
+};
+
 export const formatInteger = (num: number) => {
   return new Intl.NumberFormat('es-AR').format(num);
 };
@@ -23,7 +35,7 @@ export const formatFullDateTime = (dateString: string) => {
     year: 'numeric',
     hour: '2-digit',
     minute: '2-digit',
-    hourCycle: 'h23', // <--- LA CLAVE PARA EL FORMATO 24HS
+    hourCycle: 'h23',
     timeZone: 'America/Argentina/Buenos_Aires',
   });
 };