From 8040ea302bcd95ea7e3e85a2dd7d62f203e4dc5a Mon Sep 17 00:00:00 2001
From: Bortlesboat <169967362+Bortlesboat@users.noreply.github.com>
Date: Wed, 30 Sep 2026 00:04:15 -0400
Subject: [PATCH] fix(technical): resolve missing Fibonacci start dates against
 start date

---
 .../technical/openbb_technical/helpers.py        |  4 +++-
 .../extensions/technical/tests/test_helpers.py   | 16 ++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/openbb_platform/extensions/technical/openbb_technical/helpers.py b/openbb_platform/extensions/technical/openbb_technical/helpers.py
index 6612b4f968f8..5db509acfd70 100644
--- a/openbb_platform/extensions/technical/openbb_technical/helpers.py
+++ b/openbb_platform/extensions/technical/openbb_technical/helpers.py
@@ -555,7 +555,9 @@ def calculate_fib_levels(
 
     if start_date and end_date:
         if start_date not in data.index:
-            date0 = data.index[data.index.get_indexer([end_date], method="nearest")[0]]
+            date0 = data.index[
+                data.index.get_indexer([start_date], method="nearest")[0]
+            ]
             warn(f"Start date not in data.  Using nearest: {date0}")
         else:
             date0 = start_date
diff --git a/openbb_platform/extensions/technical/tests/test_helpers.py b/openbb_platform/extensions/technical/tests/test_helpers.py
index 59d4e4c4273f..4981fe38eff7 100644
--- a/openbb_platform/extensions/technical/tests/test_helpers.py
+++ b/openbb_platform/extensions/technical/tests/test_helpers.py
@@ -160,6 +160,22 @@ def test_raises_on_quantile_out_of_range(self, ohlcv_df):
 
 
 class TestCalculateFibLevels:
+    def test_snaps_missing_start_date_to_nearest(self):
+        """Resolve a missing start date against itself when choosing the endpoint."""
+        index = pd.bdate_range("2024-01-01", periods=60)
+        data = pd.DataFrame({"close": np.linspace(100, 160, 60)}, index=index)
+        start_date = pd.Timestamp("2024-01-06")  # Saturday, not in the index.
+        end_date = index[-1]
+
+        with pytest.warns(UserWarning, match="Start date not in data"):
+            _, min_date, max_date, min_pr, max_pr, _ = calculate_fib_levels(
+                data, "close", start_date=start_date, end_date=end_date
+            )
+
+        assert min_date == pd.Timestamp("2024-01-05")
+        assert max_date == end_date
+        assert max_pr > min_pr
+
     def test_default_branch(self, ohlcv_df):
         result = calculate_fib_levels(ohlcv_df, "close")
         assert result is not None