diff --git a/app/analysis/manual_lines.py b/app/analysis/manual_lines.py
index 23510ce..91fb776 100644
--- a/app/analysis/manual_lines.py
+++ b/app/analysis/manual_lines.py
@@ -54,6 +54,10 @@ class ManualLine:
     def is_comment(self) -> bool:
         return self.drawing_kind in {"comment", "symbol"}
 
+    @property
+    def is_overlay(self) -> bool:
+        return self.drawing_kind in {"comment", "symbol", "fibonacci"}
+
     @property
     def horizontal(self) -> bool:
         """A typed price level rather than a drawn trendline."""
@@ -194,7 +198,7 @@ class ManualLineStore:
         put it in a confluence cluster and fire a push notification about a
         piece of text.
         """
-        return [line.to_level() for line in self.lines.values() if not line.is_comment]
+        return [line.to_level() for line in self.lines.values() if not line.is_overlay]
 
     def drawings(self) -> list[ManualLine]:
         """Everything drawn, comments included, newest number last."""
diff --git a/app/api/routes.py b/app/api/routes.py
index 62c04df..b672c33 100644
--- a/app/api/routes.py
+++ b/app/api/routes.py
@@ -82,6 +82,7 @@ class LineCreate(BaseModel):
     line_width: int = Field(2, ge=1, le=9)
     cutoff_t: int | None = None
     armed: bool = True
+    kind: str = ""
 
 
 class PriceAlertCreate(BaseModel):
@@ -214,16 +215,17 @@ def put_ma_alerts(request: Request, payload: dict):
 
 @router.post("/lines", status_code=201)
 def create_line(request: Request, payload: LineCreate):
-    if payload.end_t == payload.anchor_t:
+    if payload.end_t == payload.anchor_t and payload.kind != "fibonacci":
         raise HTTPException(400, "Line endpoints must have different times")
+    last_t = payload.end_t if payload.end_t != payload.anchor_t else payload.anchor_t + 1
     line = ManualLine(
         id=f"ml_{uuid.uuid4().hex}",
         tf=payload.tf,
         side=payload.side,
         anchor_t=payload.anchor_t,
         anchor_p=payload.anchor_p,
-        slope=(payload.end_p - payload.anchor_p) / (payload.end_t - payload.anchor_t),
-        last_t=payload.end_t,
+        slope=(payload.end_p - payload.anchor_p) / (last_t - payload.anchor_t),
+        last_t=last_t,
         created_at=int(time.time()),
         note=payload.note,
         hidden=payload.hidden,
@@ -231,10 +233,13 @@ def create_line(request: Request, payload: LineCreate):
         line_width=payload.line_width,
         cutoff_t=payload.cutoff_t,
         armed=payload.armed,
+        kind=payload.kind,
     )
     runtime = request.app.state.runtime
     line = runtime.manual_lines.add(line)
     runtime.rebuild_levels()
+    if line.is_overlay:
+        return {**line.to_dict(), "kind": line.drawing_kind}
     return positioned_level(runtime, line.id).to_dict()
 
 
@@ -388,7 +393,7 @@ def patch_line(request: Request, line_id: str, payload: LinePatch):
     request.app.state.runtime.rebuild_levels()
     # A comment has no level form — returning one would hand the caller a shape
     # that looks like something the confluence engine tracks.
-    return line.to_dict() if line.is_comment else positioned_level(
+    return line.to_dict() if line.is_overlay else positioned_level(
         request.app.state.runtime, line.id,
     ).to_dict()
 
diff --git a/docs/implementation.md b/docs/implementation.md
index f3003a7..c883ec1 100644
--- a/docs/implementation.md
+++ b/docs/implementation.md
@@ -1207,3 +1207,12 @@ past `bars[-1].t` asked `timeToCoordinate` for that bar. Placement and
 rendering now share the same future-slot map trendlines already use
 (`indexAt` / `timeAtIndex` / `coordinateAtTime`). A mark in the right-hand
 whitespace stays there.
+
+### 2026-08-18 — Fibonacci retrace
+
+A Fibonacci tool under Tools: drag from one swing to the other, same
+two-click/drag gesture as a trendline. Stored as `kind=fibonacci` so it
+shares numbering, hide, delete and colour with other drawings, but it is
+not a confluence level. The chart draws native price lines at 0, 23.6,
+38.2, 50, 61.8, 78.6 and 100 between the two prices. 0% is the first
+click.
diff --git a/static/app.js b/static/app.js
index 6c134aa..d366e92 100644
--- a/static/app.js
+++ b/static/app.js
@@ -130,6 +130,7 @@ createApp({
     // Comments are not levels, so they never arrive over the levels socket and
     // are fetched and refreshed explicitly.
     const comments = ref([]);
+    const fibs = ref([]);
     const drawingFilter = ref('');
     const drawingKind = ref('all');
     const maAlerts = ref({ '1d': [] });
@@ -281,7 +282,15 @@ createApp({
         hidden: comment.hidden,
         comment,
       }));
-      return [...lines, ...notes].sort((a, b) => a.number - b.number);
+      const retraces = fibs.value.map(fib => ({
+        id: fib.id,
+        number: fib.number,
+        kind: 'fibonacci',
+        label: fib.note || 'fib',
+        hidden: fib.hidden,
+        line: fib,
+      }));
+      return [...lines, ...notes, ...retraces].sort((a, b) => a.number - b.number);
     });
 
     const filteredDrawings = computed(() => {
@@ -691,6 +700,10 @@ createApp({
         await createSymbol(result);
         return;
       }
+      if (result.tool === 'fibonacci') {
+        await createFibonacci(result.start, result.end);
+        return;
+      }
       if (result.tool === 'level') {
         alertPrice.value = result.price;
         await addPriceAlert();
@@ -704,7 +717,10 @@ createApp({
       if (!response.ok) return;
       const payload = await response.json();
       comments.value = (payload.drawings || []).filter(item => ['comment', 'symbol'].includes(item.kind));
+      fibs.value = (payload.drawings || []).filter(item => item.kind === 'fibonacci');
       syncComments();
+      if (chartApi) chartApi.setFibs(prefs.value.enabled.drawings
+        ? fibs.value.filter(item => !item.hidden) : []);
     }
 
     function syncComments() {
@@ -808,6 +824,27 @@ createApp({
       syncVisibleLevels();
     }
 
+    async function createFibonacci(start, end) {
+      const side = start.p <= end.p ? 'support' : 'resistance';
+      const response = await apiFetch('/api/lines', {
+        method: 'POST', headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          tf: timeframe.value, side,
+          anchor_t: start.t, anchor_p: start.p, end_t: end.t, end_p: end.p,
+          note: drawName.value, color: drawColor.value, line_width: drawWidth.value,
+          kind: 'fibonacci',
+        }),
+      });
+      if (!response.ok) {
+        console.error(`Unable to save fibonacci: HTTP ${response.status}`);
+        return;
+      }
+      await refreshComments();
+      const saved = await response.json();
+      selectedDrawing.value = saved.id;
+      selectedDrawings.value = [saved.id];
+    }
+
     async function createTrendline(first, second) {
       const [start, end] = [first, second].sort((a, b) => a.t - b.t);
       const side = start.snappedSide || end.snappedSide || drawSide.value;
@@ -980,7 +1017,7 @@ createApp({
       const saved = await response.json();
       // A comment is not a level and must not be pushed into the level list,
       // where it would be drawn as a line.
-      if (['comment', 'symbol'].includes(line.kind)) { await refreshComments(); return; }
+      if (['comment', 'symbol', 'fibonacci'].includes(line.kind)) { await refreshComments(); return; }
       levels.value = levels.value.map(level => level.id === line.id ? saved : level);
       syncVisibleLevels();
     }
@@ -1002,6 +1039,7 @@ createApp({
       });
       if (!response.ok) { console.error(`Unable to move line: HTTP ${response.status}`); return; }
       const saved = await response.json();
+      if (line.kind === 'fibonacci') { await refreshComments(); return; }
       levels.value = levels.value.map(level => level.id === line.id ? saved : level);
       syncVisibleLevels();
     }
@@ -1197,6 +1235,8 @@ createApp({
       syncVisibleLevels();
       syncComments();
       if (chartApi) chartApi.setRthEnabled(prefs.value.enabled.rth);
+      if (chartApi) chartApi.setFibs(prefs.value.enabled.drawings
+        ? fibs.value.filter(item => !item.hidden) : []);
       sendPrefs();
     }, { deep: true });
 
@@ -1233,7 +1273,9 @@ createApp({
     watch(selectedDrawing, id => {
       if (chartApi) {
         chartApi.setSelectedDrawing(id);
-        chartApi.setSelectedLine(levels.value.some(level => level.id === id) ? id : null);
+        chartApi.setSelectedLine(
+          levels.value.some(level => level.id === id) || fibs.value.some(fib => fib.id === id) ? id : null,
+        );
       }
       revealSelectedDrawing(id);
     });
diff --git a/static/chart.js b/static/chart.js
index e234067..4748c2b 100644
--- a/static/chart.js
+++ b/static/chart.js
@@ -134,6 +134,9 @@ class ConfluenceChart {
     this.overlayLayer = null;
     this.rthPrimitive = null;
     this.rthEnabled = true;
+    this.fibs = [];
+    this.fibLines = new Map();
+    this.fibPreview = null;
     this.futureSpace = null;
     this.snapDot = null;
     this.snapLabel = null;
@@ -373,6 +376,9 @@ class ConfluenceChart {
     this.previewLine = document.createElementNS('http://www.w3.org/2000/svg', 'line');
     this.previewLine.setAttribute('hidden', '');
     preview.appendChild(this.previewLine);
+    this.fibPreview = document.createElementNS('http://www.w3.org/2000/svg', 'g');
+    this.fibPreview.setAttribute('hidden', '');
+    preview.appendChild(this.fibPreview);
     this.overlayLayer.appendChild(preview);
     this.lineBridgeLayer = document.createElementNS('http://www.w3.org/2000/svg', 'svg');
     this.lineBridgeLayer.classList.add('chart-line-bridges');
@@ -684,6 +690,49 @@ class ConfluenceChart {
     }
   }
 
+  setFibs(fibs) {
+    this.fibs = fibs || [];
+    this.syncFibLines();
+    this.scheduleOverlays(true);
+  }
+
+  static fibPrices(fib) {
+    const start = Number(fib.anchor_p);
+    const end = start + Number(fib.slope || 0) * (Number(fib.last_t) - Number(fib.anchor_t));
+    return ConfluenceChart.FIB_RATIOS.map(item => ({
+      ...item,
+      price: start + (end - start) * item.r,
+    }));
+  }
+
+  syncFibLines() {
+    if (!this.candles) return;
+    const wanted = new Set();
+    for (const fib of this.fibs) {
+      if (fib.hidden) continue;
+      for (const level of ConfluenceChart.fibPrices(fib)) {
+        const id = `${fib.id}:${level.r}`;
+        wanted.add(id);
+        const options = {
+          price: level.price,
+          color: fib.color || '#c8992f',
+          lineWidth: level.r === 0 || level.r === 0.618 || level.r === 1 ? 2 : 1,
+          lineStyle: level.r === 0.618 ? LightweightCharts.LineStyle.Solid : LightweightCharts.LineStyle.Dashed,
+          axisLabelVisible: true,
+          title: `${level.label}  ${level.price.toFixed(2)}`,
+        };
+        const existing = this.fibLines.get(id);
+        if (existing) existing.applyOptions(options);
+        else this.fibLines.set(id, this.candles.createPriceLine(options));
+      }
+    }
+    for (const [id, line] of this.fibLines) {
+      if (wanted.has(id)) continue;
+      this.candles.removePriceLine(line);
+      this.fibLines.delete(id);
+    }
+  }
+
   setComments(comments) {
     this.comments = comments;
     this.scheduleOverlays(true);
@@ -1602,6 +1651,10 @@ class ConfluenceChart {
   }
 
   renderPending(a, b) {
+    if (this.armedTool === 'fibonacci') {
+      this.setFibPreview(a, b);
+      return;
+    }
     if (a.t != null && b.t != null) this.setLinePreview(a, b, '#65b7cf', 2);
   }
 
@@ -1699,7 +1752,9 @@ class ConfluenceChart {
     const a = dragged ? this.snapPoint(start) : this.pendingAnchor;
     this.pendingAnchor = null;
     this.clearLinePreview();
-    if (a.t == null || b.t == null || a.t === b.t) return;
+    if (a.t == null || b.t == null) return;
+    if (tool !== 'fibonacci' && a.t === b.t) return;
+    if (tool === 'fibonacci' && a.p === b.p) return;
     this.onToolComplete?.({ tool, start: a, end: b });
   }
 
@@ -1800,6 +1855,10 @@ class ConfluenceChart {
     }
     const a = this.snapPoint(start);
     const b = this.snapPoint(end);
+    if (this.armedTool === 'fibonacci') {
+      this.setFibPreview(a, b);
+      return;
+    }
     if (a.t != null && b.t != null) this.setLinePreview(a, b, '#65b7cf', 2);
   }
 
@@ -1879,6 +1938,28 @@ class ConfluenceChart {
     node.focusTimer = setTimeout(() => node.root.classList.remove('focus'), 800);
   }
 
+  setFibPreview(start, end) {
+    if (!this.fibPreview || start?.p == null || end?.p == null || start.p === end.p) return;
+    if (this.previewLine) this.previewLine.setAttribute('hidden', '');
+    this.fibPreview.removeAttribute('hidden');
+    this.fibPreview.replaceChildren();
+    const width = this.overlayLayer?.clientWidth || this.chartEl.clientWidth;
+    for (const item of ConfluenceChart.FIB_RATIOS) {
+      const y = this.candles.priceToCoordinate(start.p + (end.p - start.p) * item.r);
+      if (y == null) continue;
+      const line = document.createElementNS('http://www.w3.org/2000/svg', 'line');
+      line.setAttribute('x1', 0);
+      line.setAttribute('x2', width);
+      line.setAttribute('y1', y);
+      line.setAttribute('y2', y);
+      line.setAttribute('stroke', '#c8992f');
+      line.setAttribute('stroke-width', item.r === 0 || item.r === 0.618 || item.r === 1 ? 1.5 : 1);
+      if (item.r !== 0.618) line.setAttribute('stroke-dasharray', '4 4');
+      line.setAttribute('opacity', '0.75');
+      this.fibPreview.appendChild(line);
+    }
+  }
+
   setLinePreview(start, end, color, lineWidth) {
     if (start.t === end.t) return;
     const x1 = this.chart.timeScale().timeToCoordinate(start.t);
@@ -1898,6 +1979,10 @@ class ConfluenceChart {
 
   clearLinePreview() {
     if (this.previewLine) this.previewLine.setAttribute('hidden', '');
+    if (this.fibPreview) {
+      this.fibPreview.setAttribute('hidden', '');
+      this.fibPreview.replaceChildren();
+    }
   }
 
   barAtTime(time) {
@@ -1970,6 +2055,13 @@ class ConfluenceChart {
       const distance = Math.abs(lineY - param.point.y);
       if (distance <= 6 && (!best || distance < best.distance)) best = { id: level.id, distance };
     }
+    for (const fib of this.fibs.filter(item => !item.hidden)) {
+      for (const level of ConfluenceChart.fibPrices(fib)) {
+        const y = this.candles.priceToCoordinate(level.price);
+        const distance = y == null ? Infinity : Math.abs(y - param.point.y);
+        if (distance <= 6 && (!best || distance < best.distance)) best = { id: fib.id, distance };
+      }
+    }
     return best?.id || null;
   }
 
@@ -2314,10 +2406,16 @@ class ConfluenceChart {
       }));
   }
 
+  fibAsHandleLevel() {
+    const fib = this.fibs.find(item => item.id === this.selectedLineId && !item.hidden);
+    if (!fib) return null;
+    return { ...fib, kind: 'manual', slope: Number(fib.slope) || 0 };
+  }
+
   renderAnchorHandles() {
     const level = this.levels.find(
       value => value.id === this.selectedLineId && value.kind === 'manual' && !value.hidden,
-    );
+    ) || this.fibAsHandleLevel();
     if (!level || !this.anchorHandles.length) {
       this.anchorHandles.forEach(handle => handle.setAttribute('hidden', ''));
       this.lineHitTarget?.setAttribute('hidden', '');
@@ -2723,6 +2821,16 @@ class ConfluenceChart {
   }
 }
 
+ConfluenceChart.FIB_RATIOS = [
+  { r: 0, label: '0' },
+  { r: 0.236, label: '23.6' },
+  { r: 0.382, label: '38.2' },
+  { r: 0.5, label: '50' },
+  { r: 0.618, label: '61.8' },
+  { r: 0.786, label: '78.6' },
+  { r: 1, label: '100' },
+];
+
 ConfluenceChart.tfColors = {
   '1m':'#82909f', '2m':'#8a92df', '5m':'#65b7cf', '15m':'#45c39b',
   '30m':'#a8c85d', '1h':'#efb643', '1d':'#d96073',
diff --git a/static/index.html b/static/index.html
index 8f0afa2..3be568c 100644
--- a/static/index.html
+++ b/static/index.html
@@ -31,6 +31,7 @@
           <span v-if="extraDetail">HELD <b>{{ status.bars_held?.[timeframe] || 0 }} {{ timeframe }}</b></span>
           <span v-if="armedTool === 'trendline'" class="arm-hint">Drag on the chart from one point to the other</span>
           <span v-else-if="armedTool === 'level'" class="arm-hint">Click or drag on the chart to set the price</span>
+          <span v-else-if="armedTool === 'fibonacci'" class="arm-hint">Drag from one swing to the other</span>
           <span v-else-if="selectedDrawing" class="arm-hint">Drawing selected — Delete removes it</span>
           <button v-if="diagnosticMode" class="diag-capture" :disabled="captureBusy" @click="captureDiagnostic">
             {{ captureBusy ? 'CAPTURING…' : 'CAPTURE DIAGNOSTIC' }}
@@ -129,6 +130,20 @@
             <p class="hint">Drag on the chart, or type an exact price. Alerts whenever price reaches it, whatever the confluence score.</p>
           </div>
         </div>
+        <div class="tool" :class="{armed: armedTool === 'fibonacci'}">
+          <button class="tool-head" @click="armTool('fibonacci')" :aria-pressed="armedTool === 'fibonacci'">
+            <span class="tool-glyph"><i class="fa-solid fa-chart-line"></i></span>Fibonacci
+            <span class="tool-state">{{ armedTool === 'fibonacci' ? 'drag swings' : '' }}</span>
+          </button>
+          <div class="tool-body" v-show="armedTool === 'fibonacci'">
+            <label>Label<input v-model.trim="drawName" placeholder="optional" aria-label="Fibonacci label"></label>
+            <div class="row">
+              <label>Colour<input type="color" v-model="drawColor" aria-label="Fibonacci colour"></label>
+              <label>Width<select v-model.number="drawWidth" aria-label="Fibonacci width"><option v-for="width in 9" :value="width">{{ width }}px</option></select></label>
+            </div>
+            <p class="hint">Drag from one swing to the other. Levels at 0, 23.6, 38.2, 50, 61.8, 78.6 and 100.</p>
+          </div>
+        </div>
         <div class="tool tool-trendline" :class="{armed: armedTool === 'trendline'}">
           <button class="tool-head" @click="armTool('trendline')" :aria-pressed="armedTool === 'trendline'">
             <span class="tool-glyph"><i class="fa-solid fa-arrow-trend-up"></i></span>Trendline
@@ -235,6 +250,7 @@
               <option value="level">Levels</option>
               <option value="comment">Comments</option>
               <option value="symbol">Symbols</option>
+              <option value="fibonacci">Fibonacci</option>
             </select>
             <select v-model="drawingTf" aria-label="Filter drawings by timeframe">
               <option value="all">All TFs</option>
@@ -288,6 +304,7 @@
               <div class="drawing-secondary">
                 <span v-if="item.kind === 'comment'">#{{ item.number }} · NOTE · {{ item.comment.pinned ? 'PIN' : 'FLOAT' }}</span>
                 <span v-else-if="item.kind === 'symbol'">#{{ item.number }} · SYMBOL · {{ item.comment.note }}</span>
+                <span v-else-if="item.kind === 'fibonacci'">#{{ item.number }} · FIB · {{ item.label }}</span>
                 <span v-else-if="item.kind === 'level'" class="level-editors">
                   <label>Price<input type="number" min="0.25" step="0.25" :value="item.line.anchor_p"
                     aria-label="Level price in drawing list"
diff --git a/tests/test_fibonacci.py b/tests/test_fibonacci.py
new file mode 100644
index 0000000..8f87a9f
--- /dev/null
+++ b/tests/test_fibonacci.py
@@ -0,0 +1,42 @@
+from fastapi import FastAPI
+from fastapi.testclient import TestClient
+
+from app.analysis.levels import Side
+from app.analysis.manual_lines import ManualLine, ManualLineStore
+from app.api.routes import router
+from app.bars.models import Timeframe
+from app.config import Settings
+from app.runtime import Runtime
+
+
+def test_a_fibonacci_is_not_a_confluence_level(tmp_path):
+    store = ManualLineStore(tmp_path / "lines.json")
+    store.add(ManualLine(
+        id="ml_fib", tf=Timeframe.M15, side=Side.RESISTANCE,
+        anchor_t=1000, anchor_p=6500, slope=-1 / 1800, last_t=2800,
+        created_at=1000, kind="fibonacci", note="swing",
+    ))
+    assert store.levels() == []
+    assert store.drawings()[0].drawing_kind == "fibonacci"
+
+
+def test_creating_a_fibonacci_returns_the_drawing_not_a_level(tmp_path):
+    app = FastAPI()
+    app.include_router(router)
+    app.state.runtime = Runtime(Settings(
+        manual_lines_path=tmp_path / "lines.json",
+        events_path=tmp_path / "events.json",
+        alert_state_path=tmp_path / "alerts.json",
+        chart_auth_token="",
+    ))
+    client = TestClient(app)
+    response = client.post("/api/lines", json={
+        "tf": "15m", "side": "resistance",
+        "anchor_t": 1000, "anchor_p": 6500, "end_t": 2800, "end_p": 6400,
+        "kind": "fibonacci", "note": "high to low",
+    })
+    assert response.status_code == 201
+    body = response.json()
+    assert body["kind"] == "fibonacci"
+    assert "weight" not in body
+    assert app.state.runtime.manual_lines.levels() == []
diff --git a/tests/test_manual_lines.py b/tests/test_manual_lines.py
index d234852..6287a55 100644
--- a/tests/test_manual_lines.py
+++ b/tests/test_manual_lines.py
@@ -80,9 +80,11 @@ def test_an_annotation_is_never_a_level(tmp_path):
                          note="watch this", **common))
     store.add(ManualLine(id="ml_symbol", slope=0.0, kind="symbol",
                          icon="skull", note="Skull", **common))
+    store.add(ManualLine(id="ml_fib", slope=0.01, kind="fibonacci",
+                         note="fib", **common))
 
     assert [level.id for level in store.levels()] == ["ml_level"]
-    assert [line.id for line in store.drawings()] == ["ml_level", "ml_note", "ml_symbol"]
+    assert [line.id for line in store.drawings()] == ["ml_level", "ml_note", "ml_symbol", "ml_fib"]
 
 
 def test_drawing_kind_is_derived_for_lines_saved_before_comments(tmp_path):