fix: convert Finnhub market cap from millions to absolute USD

Finnhub profile2 reports marketCapitalization in millions; storing it
as dollars made mega-caps like SPCX show as micro (e.g. 1.8M). Normalize
on ingest, add unit tests, and include a one-shot SQL backfill script.

tests/unit/test_finnhub_provider.py

@@ -0,0 +1,92 @@
+"""Unit tests for FinnhubFundamentalProvider unit conversions."""
+
+from __future__ import annotations
+
+from unittest.mock import AsyncMock, patch
+
+import httpx
+import pytest
+
+from app.providers.fundamentals_chain import FinnhubFundamentalProvider
+
+
+def _mock_response(status_code: int, json_data: object = None) -> httpx.Response:
+    return httpx.Response(
+        status_code=status_code,
+        json=json_data if json_data is not None else {},
+        request=httpx.Request("GET", "https://example.com"),
+    )
+
+
+@pytest.fixture
+def provider() -> FinnhubFundamentalProvider:
+    return FinnhubFundamentalProvider(api_key="test-key")
+
+
+@pytest.mark.asyncio
+async def test_finnhub_market_cap_converted_from_millions_to_dollars(provider):
+    """Finnhub marketCapitalization is in millions — store absolute USD.
+
+    SPCX-scale example: ~$1.8T → Finnhub reports 1_800_000 (millions).
+    Without conversion the UI showed 1.8M / micro cap.
+    """
+    profile = {"marketCapitalization": 1_800_000}  # millions → $1.8T
+    metrics = {"metric": {"peTTM": 40.0, "revenueGrowthTTMYoy": 25.0}}
+    earnings = [{"surprisePercent": 2.5}]
+    calendar = {"earningsCalendar": []}
+
+    async def mock_get(url, params=None):
+        if "profile2" in url:
+            return _mock_response(200, profile)
+        if "stock/metric" in url:
+            return _mock_response(200, metrics)
+        if "stock/earnings" in url:
+            return _mock_response(200, earnings)
+        if "calendar/earnings" in url:
+            return _mock_response(200, calendar)
+        return _mock_response(200, {})
+
+    with patch("app.providers.fundamentals_chain.httpx.AsyncClient") as MockClient:
+        instance = AsyncMock()
+        instance.get.side_effect = mock_get
+        instance.__aenter__ = AsyncMock(return_value=instance)
+        instance.__aexit__ = AsyncMock(return_value=False)
+        MockClient.return_value = instance
+
+        result = await provider.fetch_fundamentals("SPCX")
+
+    assert result.market_cap == 1_800_000 * 1_000_000  # $1.8T
+    assert result.pe_ratio == 40.0
+    assert result.revenue_growth == 25.0
+    assert result.earnings_surprise == 2.5
+
+
+@pytest.mark.asyncio
+async def test_finnhub_market_cap_none_when_missing(provider):
+    profile: dict = {}
+    metrics = {"metric": {}}
+    earnings: list = []
+    calendar = {"earningsCalendar": []}
+
+    async def mock_get(url, params=None):
+        if "profile2" in url:
+            return _mock_response(200, profile)
+        if "stock/metric" in url:
+            return _mock_response(200, metrics)
+        if "stock/earnings" in url:
+            return _mock_response(200, earnings)
+        if "calendar/earnings" in url:
+            return _mock_response(200, calendar)
+        return _mock_response(200, {})
+
+    with patch("app.providers.fundamentals_chain.httpx.AsyncClient") as MockClient:
+        instance = AsyncMock()
+        instance.get.side_effect = mock_get
+        instance.__aenter__ = AsyncMock(return_value=instance)
+        instance.__aexit__ = AsyncMock(return_value=False)
+        MockClient.return_value = instance
+
+        result = await provider.fetch_fundamentals("XYZ")
+
+    assert result.market_cap is None
+    assert "market_cap" in result.unavailable_fields