diff --git a/alembic/versions/h9b0c1d2e3f4_add_interval_to_alpaca_price.py b/alembic/versions/h9b0c1d2e3f4_add_interval_to_alpaca_price.py
new file mode 100644
index 0000000..d292679
--- /dev/null
+++ b/alembic/versions/h9b0c1d2e3f4_add_interval_to_alpaca_price.py
@@ -0,0 +1,49 @@
+"""add interval column to alpaca_price_data
+
+Revision ID: h9b0c1d2e3f4
+Revises: g8a9b0c1d2e3
+Create Date: 2026-04-14
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+revision: str = "h9b0c1d2e3f4"
+down_revision: Union[str, Sequence[str], None] = "g8a9b0c1d2e3"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # 1. Add interval column (default '1d' for existing rows)
+    op.add_column(
+        "alpaca_price_data",
+        sa.Column("interval", sa.String(10), nullable=False, server_default="1d"),
+    )
+
+    # 2. Drop old unique constraint and index
+    op.drop_constraint("uq_alpaca_price_data", "alpaca_price_data", type_="unique")
+    op.drop_index("idx_alpaca_price_ticker_date", table_name="alpaca_price_data")
+
+    # 3. Create new unique constraint and index including interval
+    op.create_unique_constraint(
+        "uq_alpaca_price_data", "alpaca_price_data", ["ticker", "date", "interval"]
+    )
+    op.create_index(
+        "idx_alpaca_price_ticker_date", "alpaca_price_data", ["ticker", "date", "interval"]
+    )
+
+
+def downgrade() -> None:
+    op.drop_constraint("uq_alpaca_price_data", "alpaca_price_data", type_="unique")
+    op.drop_index("idx_alpaca_price_ticker_date", table_name="alpaca_price_data")
+
+    op.create_unique_constraint(
+        "uq_alpaca_price_data", "alpaca_price_data", ["ticker", "date"]
+    )
+    op.create_index(
+        "idx_alpaca_price_ticker_date", "alpaca_price_data", ["ticker", "date"]
+    )
+
+    op.drop_column("alpaca_price_data", "interval")
diff --git a/app/models/alpaca_price.py b/app/models/alpaca_price.py
index 961d21e..3d41806 100644
--- a/app/models/alpaca_price.py
+++ b/app/models/alpaca_price.py
@@ -25,12 +25,14 @@ class AlpacaPriceData(Base):
     vwap = Column(Float, nullable=True)          # Volume-weighted average price (Alpaca-specific)
     trade_count = Column(Integer, nullable=True)  # Number of trades (Alpaca-specific)
 
+    interval = Column(String(10), nullable=False, default='1d')  # e.g. "1d", "5m", "1h"
+
     # Metadata
     data_source = Column(String(50), default='ALPACA')
     created_at = Column(TIMESTAMP(timezone=True), default=lambda: datetime.now(timezone.utc))
     updated_at = Column(TIMESTAMP(timezone=True), default=lambda: datetime.now(timezone.utc), onupdate=lambda: datetime.now(timezone.utc))
 
     __table_args__ = (
-        UniqueConstraint('ticker', 'date', name='uq_alpaca_price_data'),
-        Index('idx_alpaca_price_ticker_date', 'ticker', 'date'),
+        UniqueConstraint('ticker', 'date', 'interval', name='uq_alpaca_price_data'),
+        Index('idx_alpaca_price_ticker_date', 'ticker', 'date', 'interval'),
     )
diff --git a/app/services/alpaca_price_service.py b/app/services/alpaca_price_service.py
index b5f4113..ab8698f 100644
--- a/app/services/alpaca_price_service.py
+++ b/app/services/alpaca_price_service.py
@@ -114,6 +114,7 @@ class AlpacaPriceService:
                 .where(
                     and_(
                         AlpacaPriceData.ticker.in_(upper_tickers),
+                        AlpacaPriceData.interval == interval,
                         AlpacaPriceData.date >= start_dt,
                         AlpacaPriceData.date <= end_dt,
                     )
@@ -151,6 +152,7 @@ class AlpacaPriceService:
                     rows.append({
                         "ticker": original,
                         "date": bar_dt,
+                        "interval": interval,
                         "open": float(bar.get("o", 0)),
                         "high": float(bar.get("h", 0)),
                         "low": float(bar.get("l", 0)),
@@ -162,8 +164,8 @@ class AlpacaPriceService:
                     })
 
             if rows:
-                # Chunk to stay under asyncpg's 32767-param limit (~10 params/row → 3000/chunk)
-                CHUNK = 3000
+                # Chunk to stay under asyncpg's 32767-param limit (~11 params/row → 2900/chunk)
+                CHUNK = 2900
                 for i in range(0, len(rows), CHUNK):
                     stmt = pg_insert(AlpacaPriceData).values(rows[i : i + CHUNK])
                     stmt = stmt.on_conflict_do_nothing(constraint="uq_alpaca_price_data")
@@ -173,12 +175,13 @@ class AlpacaPriceService:
                     f"Alpaca multi-bars: stored {len(rows)} rows for {len(need_fetch)} tickers"
                 )
 
-        # Read all data back from DB
+        # Read back from DB — filtered by interval to avoid mixing 1d/5m/etc.
         result = await db.execute(
             select(AlpacaPriceData)
             .where(
                 and_(
                     AlpacaPriceData.ticker.in_(upper_tickers),
+                    AlpacaPriceData.interval == interval,
                     AlpacaPriceData.date >= start_dt,
                     AlpacaPriceData.date <= end_dt,
                 )