Handle single asset portfolio analysis

App/analysis/portfolio_optimizer.py

@@ -449,8 +449,70 @@ async def analyze_portfolio_growth_allocation(
     simulations: int = DEFAULT_SIMULATIONS,
 ) -> dict[str, Any]:
     assets = await _build_assets(portfolio_id)
-    if len(assets) < 2:
-        raise ValueError("At least two priced assets are required for allocation analysis")
+    if not assets:
+        raise ValueError("At least one priced asset is required for allocation analysis")
+    if len(assets) == 1:
+        asset = assets[0]
+        current_stats = {
+            "expected_return": asset.expected_return,
+            "volatility": asset.volatility,
+            "sharpe": (
+                (asset.expected_return - DEFAULT_RISK_FREE_RATE) / asset.volatility
+                if asset.volatility > 0
+                else 0.0
+            ),
+        }
+        allocation = {
+            "asset_id": asset.asset_id,
+            "asset_type": asset.asset_type,
+            "symbol": asset.symbol,
+            "name": asset.name,
+            "current_weight": 1.0,
+            "suggested_weight": 1.0,
+            "difference": 0.0,
+            "current_value": round(asset.current_value, 2),
+            "suggested_value": round(asset.current_value, 2),
+            "rebalance_amount": 0.0,
+            "expected_return": round(asset.expected_return, 4),
+            "volatility": round(asset.volatility, 4),
+            "fee_rate": round(asset.fee_rate, 4),
+            "reason": "Only priced asset in portfolio; add other assets before optimization can rebalance.",
+        }
+        return {
+            "objective": "growth",
+            "total_value": round(asset.current_value, 2),
+            "risk_free_rate": DEFAULT_RISK_FREE_RATE,
+            "constraints": {
+                "max_asset_weight": 1.0,
+                "class_limits": GROWTH_CLASS_LIMITS,
+                "class_limits_apply_only_when_multiple_asset_classes_exist": True,
+            },
+            "current": {k: round(v, 4) for k, v in current_stats.items()},
+            "suggested": {k: round(v, 4) for k, v in current_stats.items()},
+            "estimated_rebalance_fees": 0.0,
+            "advisor_comment": {
+                "title": "Concentration warning",
+                "summary": (
+                    f"Your portfolio is currently 100% allocated to {asset.symbol}. "
+                    "That may have worked well, but the growth engine is concentrated in one security, "
+                    "so the next improvement is diversification rather than reweighting."
+                ),
+                "key_actions": [
+                    "Add at least one more priced asset before running a full optimizer.",
+                    "For a growth portfolio, consider blending stocks with a liquid fund, ETF, or bond exposure to reduce single-name risk.",
+                    "Keep fees in mind: adding a new DSE stock position has transaction costs, so diversify in meaningful ticket sizes.",
+                ],
+                "caution": (
+                    "The model cannot calculate an optimized allocation from one asset alone. "
+                    "It can only flag concentration risk and explain what data is missing."
+                ),
+            },
+            "allocations": [allocation],
+            "notes": [
+                "Single-asset portfolios receive a concentration analysis instead of a failed optimization.",
+                "Add at least two priced assets to enable portfolio rebalancing advice.",
+            ],
+        }
     return await asyncio.to_thread(
         _optimize_sync,
         [asset.__dict__ for asset in assets],