feat: add candlestick chart with portfolio value line (BT-004)

- Add spot_open field to BacktestDailyPoint for complete OHLC data
- Replace line chart with candlestick chart showing price OHLC
- Add portfolio value line on secondary Y-axis
- Add _chart_options_from_dict for rendering job results
- Update both render_result and render_job_result to use new chart

app/backtesting/engine.py

@@ -94,6 +94,7 @@ class SyntheticBacktestEngine:
                 BacktestDailyPoint(
                     date=day.date,
                     spot_close=day.close,
+                    spot_open=day.open if day.open is not None else day.close,
                     spot_low=day.low if day.low is not None else day.close,
                     spot_high=day.high if day.high is not None else day.close,
                     underlying_value=underlying_value_close,

app/models/backtest.py

@@ -98,7 +98,8 @@ class BacktestDailyPoint:
     margin_call_unhedged: bool
     margin_call_hedged: bool
     active_position_ids: tuple[str, ...] = field(default_factory=tuple)
-    # Optional OHLC fields for worst-case margin call evaluation
+    # OHLC fields for chart and margin call evaluation
+    spot_open: float | None = None  # Day's open
     spot_low: float | None = None  # Day's low for margin call evaluation
     spot_high: float | None = None  # Day's high
     # Option position info

app/pages/backtests.py

@@ -116,38 +116,135 @@ def validate_numeric_inputs(
 
 
 def _chart_options(result: BacktestPageRunResult) -> dict:
+    """Create ECharts options for candlestick chart with portfolio value line."""
     template_result = result.run_result.template_results[0]
+    dates = [point.date.isoformat() for point in template_result.daily_path]
+
+    # Candlestick data: [open, close, low, high]
+    candlestick_data = [
+        [
+            point.spot_open or point.spot_close,
+            point.spot_close,
+            point.spot_low or point.spot_close,
+            point.spot_high or point.spot_close,
+        ]
+        for point in template_result.daily_path
+    ]
+
+    # Portfolio value data
+    portfolio_values = [round(point.net_portfolio_value, 2) for point in template_result.daily_path]
+
     return {
-        "tooltip": {"trigger": "axis"},
+        "tooltip": {
-        "legend": {"data": ["Spot", "LTV hedged", "LTV unhedged"]},
+            "trigger": "axis",
-        "xAxis": {"type": "category", "data": [point.date.isoformat() for point in template_result.daily_path]},
+            "axisPointer": {"type": "cross"},
+        },
+        "legend": {"data": ["Price", "Portfolio Value"]},
+        "grid": {"right": "20%"},
+        "xAxis": {"type": "category", "data": dates, "axisLabel": {"rotate": 45}},
         "yAxis": [
-            {"type": "value", "name": "Spot"},
+            {
-            {"type": "value", "name": "LTV", "min": 0, "max": 1, "axisLabel": {"formatter": "{value}"}},
+                "type": "value",
+                "name": "Price",
+                "position": "left",
+                "scale": True,
+            },
+            {
+                "type": "value",
+                "name": "Portfolio Value",
+                "position": "right",
+                "scale": True,
+            },
         ],
         "series": [
             {
-                "name": "Spot",
+                "name": "Price",
-                "type": "line",
+                "type": "candlestick",
-                "smooth": True,
+                "data": candlestick_data,
-                "data": [round(point.spot_close, 2) for point in template_result.daily_path],
+                "itemStyle": {
-                "lineStyle": {"color": "#0ea5e9"},
+                    "color": "#22c55e",  # Green for up
+                    "color0": "#ef4444",  # Red for down
+                    "borderColor": "#22c55e",
+                    "borderColor0": "#ef4444",
+                },
             },
             {
-                "name": "LTV hedged",
+                "name": "Portfolio Value",
                 "type": "line",
                 "yAxisIndex": 1,
                 "smooth": True,
-                "data": [round(point.ltv_hedged, 4) for point in template_result.daily_path],
+                "data": portfolio_values,
-                "lineStyle": {"color": "#22c55e"},
+                "lineStyle": {"color": "#0ea5e9", "width": 2},
+                "symbol": "none",
+            },
+        ],
+    }
+
+
+def _chart_options_from_dict(result: dict) -> dict:
+    """Create ECharts options from serialized job result dict."""
+    template_results = result.get("template_results", [])
+    first_template = template_results[0] if template_results else {}
+    daily_path = first_template.get("daily_path", [])
+
+    dates = [dp.get("date", "") for dp in daily_path]
+
+    # Candlestick data: [open, close, low, high]
+    candlestick_data = [
+        [
+            dp.get("spot_open", dp.get("spot_close", 0)),
+            dp.get("spot_close", 0),
+            dp.get("spot_low", dp.get("spot_close", 0)),
+            dp.get("spot_high", dp.get("spot_close", 0)),
+        ]
+        for dp in daily_path
+    ]
+
+    # Portfolio value data
+    portfolio_values = [round(dp.get("net_portfolio_value", 0), 2) for dp in daily_path]
+
+    return {
+        "tooltip": {
+            "trigger": "axis",
+            "axisPointer": {"type": "cross"},
+        },
+        "legend": {"data": ["Price", "Portfolio Value"]},
+        "grid": {"right": "20%"},
+        "xAxis": {"type": "category", "data": dates, "axisLabel": {"rotate": 45}},
+        "yAxis": [
+            {
+                "type": "value",
+                "name": "Price",
+                "position": "left",
+                "scale": True,
             },
             {
-                "name": "LTV unhedged",
+                "type": "value",
+                "name": "Portfolio Value",
+                "position": "right",
+                "scale": True,
+            },
+        ],
+        "series": [
+            {
+                "name": "Price",
+                "type": "candlestick",
+                "data": candlestick_data,
+                "itemStyle": {
+                    "color": "#22c55e",
+                    "color0": "#ef4444",
+                    "borderColor": "#22c55e",
+                    "borderColor0": "#ef4444",
+                },
+            },
+            {
+                "name": "Portfolio Value",
                 "type": "line",
                 "yAxisIndex": 1,
                 "smooth": True,
-                "data": [round(point.ltv_unhedged, 4) for point in template_result.daily_path],
+                "data": portfolio_values,
-                "lineStyle": {"color": "#ef4444"},
+                "lineStyle": {"color": "#0ea5e9", "width": 2},
+                "symbol": "none",
             },
         ],
     }
@@ -1030,6 +1127,12 @@ def _render_backtests_page(workspace_id: str | None = None) -> None:
                                 row_key="date",
                             ).classes("w-full")
 
+                    # Add candlestick chart with portfolio value
+                    if daily_path:
+                        ui.echart(_chart_options_from_dict(result)).classes(
+                            "h-96 w-full rounded-2xl border border-slate-200 bg-white p-4 shadow-sm dark:border-slate-800 dark:bg-slate-900"
+                        )
+
             # Update cost estimate for Databento
             if str(data_source_select.value) == "databento":
                 update_cost_estimate()

app/services/backtesting/jobs.py

@@ -259,6 +259,7 @@ def run_backtest_job(
                         {
                             "date": dp.date.isoformat(),
                             "spot_close": dp.spot_close,
+                            "spot_open": dp.spot_open if dp.spot_open is not None else dp.spot_close,
                             "spot_low": dp.spot_low if dp.spot_low is not None else dp.spot_close,
                             "spot_high": dp.spot_high if dp.spot_high is not None else dp.spot_close,
                             "underlying_value": dp.underlying_value,

docs/roadmap/ROADMAP.yaml

@@ -13,7 +13,6 @@ notes:
   - Pre-alpha policy: we may cut or replace old features without backward compatibility until alpha is declared.
   - Alpha migration policy: once alpha is declared, compatibility only needs to move forward; backward migrations are not required.
 priority_queue:
-  - BT-004
   - EXEC-002
   - DATA-DB-005
   - DATA-002A
@@ -24,6 +23,7 @@ priority_queue:
   - GCF-001
   - DATA-DB-006
 recently_completed:
+  - BT-004
   - BT-005
   - CORE-003
   - CONV-001
@@ -50,7 +50,6 @@ recently_completed:
   - CORE-002B
 states:
   backlog:
-    - BT-004
     - DATA-DB-005
     - DATA-DB-006
     - EXEC-002
@@ -62,6 +61,7 @@ states:
     - GCF-001
   in_progress: []
   done:
+    - BT-004
     - BT-005
     - CORE-003
     - CONV-001

docs/roadmap/done/BT-004-backtest-visualization-chart.yaml

@@ -1,6 +1,6 @@
 id: BT-004
 title: Backtest Visualization Chart
-status: backlog
+status: done
 priority: P1
 effort: M
 depends_on:
@@ -14,6 +14,6 @@ acceptance_criteria:
   - Chart is responsive and readable on mobile/tablet viewports.
   - Chart library matches existing app styling (dark mode support).
 notes: |
-  Consider using a lightweight charting library that integrates well with NiceGUI.
+  Implemented using ECharts candlestick series with portfolio value line on secondary Y-axis.
-  Portfolio value line should be clearly distinguishable from candlesticks.
+  Added spot_open field to BacktestDailyPoint for complete OHLC data.
-  May want to add toggle for showing/hiding different series.
+  Charts render for both immediate results and async job results.