feat: strategy builder

backend/routers/strategy_builder.py

@@ -15,6 +15,15 @@ from services.database import (
 router = APIRouter(prefix="/api/strategy-builder", tags=["strategy-builder"])
 
 
+class PathPointIn(BaseModel):
+    """One anchor point of a scenario time-path: `value` is in the same unit as the
+    scalar field it overrides (spot_shock_pct: %, iv_level_shift: vol pts, skew_tilt/
+    term_slope_shift: same units as their scalar counterparts). `day` is elapsed days
+    from entry (0 = today)."""
+    day: float
+    value: float
+
+
 class LegIn(BaseModel):
     expiry_date: str
     days_to_expiry: int
@@ -33,6 +42,19 @@ class ScenarioIn(BaseModel):
     term_slope_shift: float = 0.0  # term-structure slope, per 30 days (0 at days=0)
     rate_shock_bps: float = 0.0
     manual_grid: Optional[List[Dict[str, Any]]] = None
+    # Optional time-paths: when given, the /price payoff table prices each day-row against
+    # the path's own interpolated value at that day (see services.scenario_path and
+    # payoff_heatmap's surface_at_day) instead of the single terminal shock applied
+    # uniformly across every day. spot_shock_pct/iv_level_shift/skew_tilt/term_slope_shift
+    # remain the fallback for days outside the path (and the only inputs when no path is
+    # given at all) and are also what /optimize and /suggested-profile still read — those
+    # endpoints price a single scenario point, not a full trajectory, and are unaffected
+    # by these fields. See services/lib/scenarioPath.ts for how shapes (bell/oscillation/
+    # exponential/step/custom) turn into these plain anchor-point lists.
+    spot_path: Optional[List[PathPointIn]] = None
+    iv_path: Optional[List[PathPointIn]] = None
+    skew_path: Optional[List[PathPointIn]] = None
+    term_path: Optional[List[PathPointIn]] = None
     rate: float = 0.05
     n_expiries: int = 3
     contract_size: float = DEFAULT_CONTRACT_SIZE
@@ -131,6 +153,24 @@ class StrategySaveRequest(BaseModel):
     source: str = "synthetic"  # "synthetic" (Construire) | "historical" (Analyse période historique)
 
 
+def _resolve_terminal_shocks(scenario: "ScenarioIn"):
+    """The single point-in-time shock at horizon_days — from the path's own interpolated
+    value there when a path is given, otherwise the plain scalar (unchanged behavior).
+    This is what /optimize, /suggested-profile, and the entry/scenario cost figures use;
+    the day-by-day payoff table (payoff_heatmap) reads the full path directly instead."""
+    from services.scenario_path import interpolate_path
+    spot_pts = [p.model_dump() for p in scenario.spot_path] if scenario.spot_path else None
+    iv_pts = [p.model_dump() for p in scenario.iv_path] if scenario.iv_path else None
+    skew_pts = [p.model_dump() for p in scenario.skew_path] if scenario.skew_path else None
+    term_pts = [p.model_dump() for p in scenario.term_path] if scenario.term_path else None
+    return (
+        interpolate_path(spot_pts, scenario.horizon_days, scenario.spot_shock_pct),
+        interpolate_path(iv_pts, scenario.horizon_days, scenario.iv_level_shift),
+        interpolate_path(skew_pts, scenario.horizon_days, scenario.skew_tilt),
+        interpolate_path(term_pts, scenario.horizon_days, scenario.term_slope_shift),
+    )
+
+
 def _build_surfaces(scenario: ScenarioIn):
     chain_slice = get_chain_slice(
         scenario.symbol, scenario.horizon_days, scenario.n_expiries,
@@ -146,12 +186,13 @@ def _build_surfaces(scenario: ScenarioIn):
         )
         surface_scenario = build_surface(checkpoint_chain)
     else:
+        spot_shock, iv_shift, skew_tilt, term_slope = _resolve_terminal_shocks(scenario)
         surface_scenario = apply_scenario(
             surface_now,
-            spot_shock_pct=scenario.spot_shock_pct,
+            spot_shock_pct=spot_shock,
-            iv_level_shift=scenario.iv_level_shift,
+            iv_level_shift=iv_shift,
-            skew_tilt=scenario.skew_tilt,
+            skew_tilt=skew_tilt,
-            term_slope_shift=scenario.term_slope_shift,
+            term_slope_shift=term_slope,
             manual_grid=scenario.manual_grid,
         )
     return chain_slice, surface_now, surface_scenario
@@ -220,10 +261,23 @@ def price(req: PriceRequest):
         raise HTTPException(status_code=404, detail=str(e))
 
     legs = [leg.model_dump() for leg in req.legs]
+    # Paths only drive the day-by-day payoff table, and only make sense for the synthetic
+    # parametric scenario — "Analyse période historique" (checkpoint_as_of) prices against
+    # a real remembered chain instead, which has no notion of a hypothesized path.
+    use_paths = not req.scenario.checkpoint_as_of
     result = payoff_curves(
         legs, chain_slice, surface_now, surface_scenario,
         req.scenario.horizon_days, req.scenario.shocked_rate,
         contract_size=req.scenario.contract_size,
+        spot_path=([p.model_dump() for p in req.scenario.spot_path] if use_paths and req.scenario.spot_path else None),
+        iv_path=([p.model_dump() for p in req.scenario.iv_path] if use_paths and req.scenario.iv_path else None),
+        skew_path=([p.model_dump() for p in req.scenario.skew_path] if use_paths and req.scenario.skew_path else None),
+        term_path=([p.model_dump() for p in req.scenario.term_path] if use_paths and req.scenario.term_path else None),
+        base_spot_shock_pct=req.scenario.spot_shock_pct,
+        base_iv_level_shift=req.scenario.iv_level_shift,
+        base_skew_tilt=req.scenario.skew_tilt,
+        base_term_slope_shift=req.scenario.term_slope_shift,
+        manual_grid=req.scenario.manual_grid,
     )
     result["spot"] = chain_slice["spot"]
     result["scenario_spot"] = surface_scenario.spot

backend/services/scenario_path.py

@@ -0,0 +1,31 @@
+"""
+Time-path scenario support: lets a scenario describe an evolving trajectory (bell, range/
+oscillation, exponential, step, custom points...) for spot shock / IV level / skew tilt /
+term slope across the days between entry and the scenario horizon, instead of only a single
+point-in-time shock. The frontend is responsible for turning a shape+params choice into a
+plain list of {day, value} anchor points (services/lib/scenarioPath.ts) — this module only
+interpolates whatever anchor points it's given, so it has no notion of "bell" or
+"oscillation" itself and stays reusable across spot/IV/skew/term alike.
+
+A path is optional everywhere it's accepted: when None/empty, every call site here falls
+back to the scalar shock value it already had (unchanged behavior from before paths existed).
+"""
+from typing import Any, Dict, List, Optional
+
+
+def interpolate_path(path: Optional[List[Dict[str, Any]]], day: float, default: float) -> float:
+    """Linear interpolation between anchor points {day, value}, clamped flat beyond the
+    first/last anchor. Falls back to `default` when no path is given at all."""
+    if not path:
+        return default
+    pts = sorted(path, key=lambda p: p["day"])
+    if day <= pts[0]["day"]:
+        return pts[0]["value"]
+    if day >= pts[-1]["day"]:
+        return pts[-1]["value"]
+    for p0, p1 in zip(pts, pts[1:]):
+        if p0["day"] <= day <= p1["day"]:
+            span = p1["day"] - p0["day"]
+            w = (day - p0["day"]) / span if span > 1e-9 else 0.0
+            return p0["value"] + (p1["value"] - p0["value"]) * w
+    return pts[-1]["value"]

backend/services/strategy_engine.py

@@ -7,14 +7,15 @@ A "leg" dict: {expiry_date, days_to_expiry, strike, option_type ("call"/"put"),
                position ("long"/"short"), quantity}
 """
 import math
-from typing import Any, Dict, List, Optional
+from typing import Any, Callable, Dict, List, Optional
 
 import numpy as np
 from scipy.optimize import minimize_scalar
 
 from services.options_pricer import black_scholes
 from services.option_chain import find_quote
-from services.vol_surface import Surface, ScenarioSurface
+from services.vol_surface import Surface, ScenarioSurface, apply_scenario
+from services.scenario_path import interpolate_path
 
 DEFAULT_SPREAD_PCT = 0.05  # fallback relative bid/ask spread when no live quote is found
 DEFAULT_CONTRACT_SIZE = 100_000  # notional per 1 contract/lot (e.g. a standard FX lot); "quantity" on a leg is the number of these
@@ -408,8 +409,8 @@ def _find_breakevens(
 
 
 def payoff_heatmap(
-    legs: List[Dict[str, Any]], surface: Any, eval_days_expiry: float, r: float, spot: float,
+    legs: List[Dict[str, Any]], surface_at_day: Callable[[float], Any], eval_days_expiry: float, r: float,
-    entry_ref: float, contract_size: float = DEFAULT_CONTRACT_SIZE, n_prices: int = 17, n_days: int = 7,
+    spot: float, entry_ref: float, contract_size: float = DEFAULT_CONTRACT_SIZE, n_prices: int = 17, n_days: int = 7,
 ) -> Dict[str, Any]:
     """Price x days-to-expiry grid of P&L — rows are elapsed-day checkpoints from today down
     to expiry (top-to-bottom reading matches watching the position age). Columns are
@@ -418,12 +419,20 @@ def payoff_heatmap(
     window left more than half the grid flat at max loss/gain for a near-the-money position,
     wasting resolution nowhere near where the P&L actually transitions. The exact expiry
     breakeven(s) are pinned in as extra columns (breakeven_prices in the response) instead
-    of only ever landing near one by luck of the price sampling."""
+    of only ever landing near one by luck of the price sampling.
+
+    `surface_at_day` is a function of elapsed days -> a Surface-like object (.iv_at), called
+    ONCE per row rather than per cell. When the scenario has no time-path, the caller just
+    passes a constant `lambda d: surface_scenario` (today's single-shock behavior, unchanged);
+    with a path, each row gets its own interpolated spot/IV/skew/term shock — e.g. a vol pop
+    described for day 4 onward actually raises the extrinsic value in that row (and every
+    later one), not just at whatever single instant the old single-point scenario evaluated."""
     strikes = [l["strike"] for l in legs if l["option_type"] != "stock"]
     half_width = max(max(abs(spot - k) for k in strikes) * 1.4, spot * 0.03) if strikes else spot * 0.15
     lo, hi = max(spot - half_width, spot * 0.01), spot + half_width
 
-    breakevens = _find_breakevens(legs, surface, eval_days_expiry, r, entry_ref, spot, contract_size)
+    surface_at_expiry = surface_at_day(eval_days_expiry)
+    breakevens = _find_breakevens(legs, surface_at_expiry, eval_days_expiry, r, entry_ref, spot, contract_size)
     near_breakevens = sorted((p for p in breakevens if lo <= p <= hi), key=lambda p: abs(p - spot))[:2]
 
     price_points = np.unique(np.concatenate([np.linspace(lo, hi, n_prices), np.array(near_breakevens)]))
@@ -437,11 +446,12 @@ def payoff_heatmap(
     rows = []
     for d in day_points:
         d = float(d)
+        surf = surface_at_day(d)
         pnl_row, delta_row, gamma_row, theta_row, vega_row, rho_row = [], [], [], [], [], []
         for p in price_points:
             p = float(p)
-            pnl_row.append(round(float(value_at(legs, p, d, surface, r, contract_size) - entry_ref), 2))
+            pnl_row.append(round(float(value_at(legs, p, d, surf, r, contract_size) - entry_ref), 2))
-            g = greeks_at(legs, p, d, surface, r)
+            g = greeks_at(legs, p, d, surf, r)
             # greeks_at's own round() leaves numpy float64 as numpy float64 (round() doesn't
             # coerce to native Python) — black_scholes is scipy-backed, and FastAPI's default
             # JSON encoder can't serialize a bare numpy scalar (unlike pnl_row above, which
@@ -471,12 +481,35 @@ def payoff_curves(
     horizon_days: int,
     r: float = 0.05,
     contract_size: float = DEFAULT_CONTRACT_SIZE,
+    spot_path: Optional[List[Dict[str, Any]]] = None,
+    iv_path: Optional[List[Dict[str, Any]]] = None,
+    skew_path: Optional[List[Dict[str, Any]]] = None,
+    term_path: Optional[List[Dict[str, Any]]] = None,
+    base_spot_shock_pct: float = 0.0,
+    base_iv_level_shift: float = 0.0,
+    base_skew_tilt: float = 0.0,
+    base_term_slope_shift: float = 0.0,
+    manual_grid: Optional[List[Dict[str, Any]]] = None,
 ) -> Dict[str, Any]:
     spot = chain_slice["spot"]
     priced = price_combo(legs, chain_slice, surface_now, surface_scenario, horizon_days, r, contract_size)
     entry_ref = priced["entry_cost"]
     eval_days_expiry = min(l["days_to_expiry"] for l in legs)
 
-    heatmap = payoff_heatmap(legs, surface_scenario, eval_days_expiry, r, spot, entry_ref, contract_size)
+    if spot_path or iv_path or skew_path or term_path:
+        def surface_at_day(d: float):
+            return apply_scenario(
+                surface_now,
+                spot_shock_pct=interpolate_path(spot_path, d, base_spot_shock_pct),
+                iv_level_shift=interpolate_path(iv_path, d, base_iv_level_shift),
+                skew_tilt=interpolate_path(skew_path, d, base_skew_tilt),
+                term_slope_shift=interpolate_path(term_path, d, base_term_slope_shift),
+                manual_grid=manual_grid,
+            )
+    else:
+        def surface_at_day(d: float):
+            return surface_scenario
+
+    heatmap = payoff_heatmap(legs, surface_at_day, eval_days_expiry, r, spot, entry_ref, contract_size)
 
     return {"heatmap": heatmap, **priced}

frontend/src/hooks/useApi.ts

@@ -1743,6 +1743,14 @@ export type ChainSlice = { symbol: string; proxy: string; spot: number; as_of?:
 
 export type ManualGridCell = { days_to_expiry: number; strike_pct: number; iv: number | null }
 
+// One anchor point of a scenario time-path: `value` is in the same unit as the scalar
+// field it overrides (spot: %, iv: vol pts, skew/term: same units as their scalar
+// counterparts). `day` is elapsed days from entry (0 = today). See lib/scenarioPath.ts
+// for turning a shape (bell/oscillation/exponential/step/custom) into this plain list —
+// the backend (services/scenario_path.py) only ever interpolates points, it has no
+// notion of "shapes" itself.
+export type PathPoint = { day: number; value: number }
+
 export type StrategyScenario = {
   symbol: string
   horizon_days: number
@@ -1752,6 +1760,15 @@ export type StrategyScenario = {
   term_slope_shift: number
   rate_shock_bps?: number
   manual_grid?: ManualGridCell[]
+  // Optional time-paths driving the day-by-day payoff table (see payoff_heatmap on the
+  // backend) — when omitted, pricing behaves exactly as the plain scalar shock above
+  // (unchanged, single point-in-time scenario). The scalar fields above remain what
+  // /optimize and /suggested-profile read (single scenario point), and also serve as the
+  // fallback value for days outside whichever path IS given.
+  spot_path?: PathPoint[] | null
+  iv_path?: PathPoint[] | null
+  skew_path?: PathPoint[] | null
+  term_path?: PathPoint[] | null
   rate?: number
   n_expiries?: number
   contract_size?: number

frontend/src/lib/scenarioPath.ts

@@ -0,0 +1,89 @@
+// Turns a shape + params choice into a plain list of {day, value} anchor points — the
+// backend (services/scenario_path.py) only ever interpolates whatever points it's given,
+// it has no notion of "bell" or "oscillation" itself. This is the one place shapes are
+// defined, reused for all four scenario dimensions (spot shock %, IV level shift in vol
+// points, skew tilt, term slope shift) via the same PathParams shape.
+import type { PathPoint } from '../hooks/useApi'
+
+export type PathShape = 'point' | 'linear' | 'bell' | 'oscillation' | 'exponential' | 'step' | 'custom'
+
+export const PATH_SHAPES: { key: PathShape; label: string; hint: string }[] = [
+  { key: 'point', label: 'Ponctuel', hint: "Un seul choc à l'horizon, comme avant — pas de trajectoire." },
+  { key: 'linear', label: 'Linéaire', hint: 'Évolution progressive et régulière vers la valeur finale.' },
+  { key: 'bell', label: 'Cloche', hint: 'Monte vers un pic à un jour donné, puis revient vers la valeur finale.' },
+  { key: 'oscillation', label: 'Oscillation (range)', hint: 'Va-et-vient autour de zéro — plusieurs cycles possibles.' },
+  { key: 'exponential', label: 'Exponentielle', hint: 'Mouvement qui accélère (ou décélère) vers la valeur finale.' },
+  { key: 'step', label: 'Palier', hint: 'Reste plat puis bascule nettement à un jour donné (ex: pic de vol le jeudi).' },
+  { key: 'custom', label: 'Personnalisé', hint: 'Points définis à la main.' },
+]
+
+export type PathParams = {
+  shape: PathShape
+  finalValue: number // value reached at horizon_days (linear/exponential/step's post-jump level)
+  amplitude: number // bell peak height above the linear baseline / oscillation half-amplitude / step jump size
+  peakDay: number // bell: day of the peak
+  stepDay: number // step: day of the jump; oscillation/bell reuse it as a phase anchor where relevant
+  cycles: number // oscillation: number of full cycles across the horizon
+  curvature: number // exponential: shape parameter k (0 = linear-ish; >0 back-loaded; <0 front-loaded)
+  customPoints: PathPoint[] // used when shape === 'custom'
+}
+
+export function defaultPathParams(finalValue = 0): PathParams {
+  return {
+    shape: 'point', finalValue, amplitude: 0, peakDay: 1, stepDay: 1, cycles: 1, curvature: 2,
+    customPoints: [{ day: 0, value: 0 }, { day: 1, value: finalValue }],
+  }
+}
+
+/** Dense sample of the shape as {day, value} points across [0, horizonDays], for both the
+ * live sparkline preview and the payload sent to the backend (which just interpolates). */
+export function generatePath(params: PathParams, horizonDays: number, nSamples = 24): PathPoint[] {
+  const h = Math.max(horizonDays, 0.001)
+  if (params.shape === 'custom') {
+    return [...params.customPoints].sort((a, b) => a.day - b.day)
+  }
+  const pts: PathPoint[] = []
+  for (let i = 0; i <= nSamples; i++) {
+    const day = (h * i) / nSamples
+    pts.push({ day: round4(day), value: round4(valueAt(params, day, h)) })
+  }
+  return pts
+}
+
+function valueAt(params: PathParams, day: number, horizonDays: number): number {
+  const t = horizonDays > 0 ? day / horizonDays : 1
+  const { shape, finalValue, amplitude, peakDay, stepDay, cycles, curvature } = params
+  switch (shape) {
+    case 'point':
+      // Flat at 0 until the very last instant, then the terminal value — matches today's
+      // "single shock evaluated only at horizon_days" behavior if ever sampled mid-path.
+      return day >= horizonDays - 1e-6 ? finalValue : 0
+    case 'linear':
+      return finalValue * t
+    case 'bell': {
+      const tp = horizonDays > 0 ? Math.min(Math.max(peakDay / horizonDays, 1e-3), 1 - 1e-3) : 0.5
+      // Smooth hump peaking at tp, riding on top of the linear path to finalValue, built
+      // from two half-cosine lobes so the peak day is adjustable without distorting the
+      // endpoints (bump is exactly 0 at t=0 and t=1).
+      const bump = t <= tp
+        ? amplitude * (1 - Math.cos(Math.PI * (t / tp))) / 2
+        : amplitude * (1 - Math.cos(Math.PI * (1 - (t - tp) / (1 - tp)))) / 2
+      return finalValue * t + bump
+    }
+    case 'oscillation':
+      return finalValue * t + amplitude * Math.sin(2 * Math.PI * cycles * t)
+    case 'exponential': {
+      const k = curvature
+      if (Math.abs(k) < 1e-6) return finalValue * t
+      return finalValue * (Math.exp(k * t) - 1) / (Math.exp(k) - 1)
+    }
+    case 'step':
+      // Flat at 0, then flat at finalValue from stepDay onward — e.g. "vol calme jusqu'à
+      // jeudi, puis un cran plus haut" is stepDay=3, finalValue=+8 (vol pts).
+      return day < stepDay - 1e-9 ? 0 : finalValue
+    default:
+      return 0
+  }
+}
+
+function round4(v: number) { return Math.round(v * 10000) / 10000 }

frontend/src/pages/StrategyBuilder.tsx

@@ -10,10 +10,11 @@ import {
   useSavedStrategies, useSaveStrategyRecord, useDeleteSavedStrategy,
   useSaxoSymbols, useIvForTrade,
   type StrategyLeg, type StrategyScenario, type PayoffHeatmap, type PayoffHeatmapMetric, type StrategyCandidate,
-  type OptimizeConstraints, type SavedScenario,
+  type OptimizeConstraints, type SavedScenario, type PathPoint,
   type GreekProfile, type GreekTarget, type GreekState, type GreekTolerance, DEFAULT_GREEK_PROFILE,
 } from '../hooks/useApi'
 import { fmtPrice, fmtAsOf } from '../lib/format'
+import { PATH_SHAPES, defaultPathParams, generatePath, type PathShape, type PathParams } from '../lib/scenarioPath'
 
 const STRIKE_PCTS = [80, 85, 90, 95, 100, 105, 110, 115, 120]
 const DELTA_NEUTRAL_THRESHOLD = 0.15
@@ -261,6 +262,206 @@ function ScenarioSlidersPanel({ scenario, setScenario }: { scenario: StrategySce
   )
 }
 
+// ── Scenario time-paths (trajectoire spot/vol/skew/terme) ────────────────────
+
+type PathDim = 'spot' | 'iv' | 'skew' | 'term'
+const PATH_DIM_CONFIG: Record<PathDim, {
+  label: string; scenarioKey: 'spot_shock_pct' | 'iv_level_shift' | 'skew_tilt' | 'term_slope_shift'
+  pathKey: 'spot_path' | 'iv_path' | 'skew_path' | 'term_path'
+  min: number; max: number; step: number; fmt: (v: number) => string
+}> = {
+  spot: { label: 'Trajectoire du sous-jacent', scenarioKey: 'spot_shock_pct', pathKey: 'spot_path', min: -20, max: 20, step: 0.1, fmt: (v) => `${v >= 0 ? '+' : ''}${v.toFixed(1)}%` },
+  iv: { label: 'Trajectoire de la volatilité (niveau IV)', scenarioKey: 'iv_level_shift', pathKey: 'iv_path', min: -0.15, max: 0.15, step: 0.005, fmt: (v) => `${v >= 0 ? '+' : ''}${(v * 100).toFixed(1)}pts` },
+  skew: { label: 'Trajectoire du skew', scenarioKey: 'skew_tilt', pathKey: 'skew_path', min: -0.1, max: 0.1, step: 0.005, fmt: (v) => v.toFixed(3) },
+  term: { label: 'Trajectoire de la pente du terme', scenarioKey: 'term_slope_shift', pathKey: 'term_path', min: -0.1, max: 0.1, step: 0.005, fmt: (v) => `${v >= 0 ? '+' : ''}${(v * 100).toFixed(1)}pts` },
+}
+
+function Sparkline({ points, horizonDays, width = 220, height = 44 }: { points: PathPoint[]; horizonDays: number; width?: number; height?: number }) {
+  if (!points.length) return null
+  const values = points.map(p => p.value)
+  const vMin = Math.min(0, ...values), vMax = Math.max(0, ...values)
+  const span = vMax - vMin || 1
+  const x = (day: number) => (horizonDays > 0 ? (day / horizonDays) * (width - 4) + 2 : 2)
+  const y = (v: number) => height - 4 - ((v - vMin) / span) * (height - 8)
+  const path = points.map((p, i) => `${i === 0 ? 'M' : 'L'}${x(p.day).toFixed(1)},${y(p.value).toFixed(1)}`).join(' ')
+  const zeroY = y(0)
+  return (
+    <svg width={width} height={height} className="shrink-0">
+      <line x1={0} y1={zeroY} x2={width} y2={zeroY} stroke="currentColor" strokeOpacity={0.15} strokeDasharray="3,3" />
+      <path d={path} fill="none" stroke="#38bdf8" strokeWidth={1.5} />
+    </svg>
+  )
+}
+
+function PathDimEditor({
+  dim, params, setParams, horizonDays, scenario, setScenario,
+}: {
+  dim: PathDim; params: PathParams; setParams: (p: PathParams) => void; horizonDays: number
+  scenario: StrategyScenario; setScenario: (v: StrategyScenario) => void
+}) {
+  const cfg = PATH_DIM_CONFIG[dim]
+
+  const apply = (next: PathParams) => {
+    setParams(next)
+    if (next.shape === 'point') {
+      setScenario({ ...scenario, [cfg.pathKey]: null, [cfg.scenarioKey]: next.finalValue })
+      return
+    }
+    const path = generatePath(next, horizonDays)
+    setScenario({ ...scenario, [cfg.pathKey]: path, [cfg.scenarioKey]: next.finalValue })
+  }
+
+  const preview = params.shape === 'point' ? [{ day: 0, value: 0 }, { day: horizonDays, value: params.finalValue }] : generatePath(params, horizonDays)
+
+  return (
+    <div className="space-y-2 border-t border-slate-800/60 pt-3 first:border-0 first:pt-0">
+      <div className="flex items-center justify-between gap-3">
+        <div className="text-xs text-slate-400">{cfg.label}</div>
+        <select
+          value={params.shape}
+          onChange={(e) => apply({ ...params, shape: e.target.value as PathShape })}
+          className="bg-dark-700 border border-slate-700/50 rounded px-2 py-1 text-xs text-slate-200"
+        >
+          {PATH_SHAPES.map(s => <option key={s.key} value={s.key}>{s.label}</option>)}
+        </select>
+      </div>
+
+      <div className="flex items-center gap-3">
+        <Sparkline points={preview} horizonDays={horizonDays} />
+        <div className="flex-1 grid grid-cols-2 gap-2 text-xs">
+          {params.shape !== 'custom' && (
+            <label className="flex items-center justify-between gap-2 text-slate-400">
+              {params.shape === 'step' ? 'Niveau après le palier' : 'Valeur finale (J+' + horizonDays + ')'}
+              <input
+                type="number" step={cfg.step} value={params.finalValue}
+                onChange={(e) => apply({ ...params, finalValue: parseFloat(e.target.value) || 0 })}
+                className="w-24 bg-dark-700 border border-slate-700/50 rounded px-1.5 py-0.5 text-slate-200 text-right"
+              />
+            </label>
+          )}
+          {(params.shape === 'bell' || params.shape === 'oscillation') && (
+            <label className="flex items-center justify-between gap-2 text-slate-400">
+              {params.shape === 'bell' ? 'Amplitude du pic' : 'Amplitude'}
+              <input
+                type="number" step={cfg.step} value={params.amplitude}
+                onChange={(e) => apply({ ...params, amplitude: parseFloat(e.target.value) || 0 })}
+                className="w-24 bg-dark-700 border border-slate-700/50 rounded px-1.5 py-0.5 text-slate-200 text-right"
+              />
+            </label>
+          )}
+          {params.shape === 'bell' && (
+            <label className="flex items-center justify-between gap-2 text-slate-400">
+              Jour du pic
+              <input
+                type="number" min={0} max={horizonDays} step={0.5} value={params.peakDay}
+                onChange={(e) => apply({ ...params, peakDay: parseFloat(e.target.value) || 0 })}
+                className="w-24 bg-dark-700 border border-slate-700/50 rounded px-1.5 py-0.5 text-slate-200 text-right"
+              />
+            </label>
+          )}
+          {params.shape === 'oscillation' && (
+            <label className="flex items-center justify-between gap-2 text-slate-400">
+              Cycles sur la période
+              <input
+                type="number" min={0.5} step={0.5} value={params.cycles}
+                onChange={(e) => apply({ ...params, cycles: parseFloat(e.target.value) || 1 })}
+                className="w-24 bg-dark-700 border border-slate-700/50 rounded px-1.5 py-0.5 text-slate-200 text-right"
+              />
+            </label>
+          )}
+          {params.shape === 'exponential' && (
+            <label className="flex items-center justify-between gap-2 text-slate-400">
+              Courbure (k)
+              <input
+                type="number" step={0.5} value={params.curvature}
+                onChange={(e) => apply({ ...params, curvature: parseFloat(e.target.value) || 0 })}
+                className="w-24 bg-dark-700 border border-slate-700/50 rounded px-1.5 py-0.5 text-slate-200 text-right"
+              />
+            </label>
+          )}
+          {params.shape === 'step' && (
+            <label className="flex items-center justify-between gap-2 text-slate-400">
+              Jour du palier
+              <input
+                type="number" min={0} max={horizonDays} step={0.5} value={params.stepDay}
+                onChange={(e) => apply({ ...params, stepDay: parseFloat(e.target.value) || 0 })}
+                className="w-24 bg-dark-700 border border-slate-700/50 rounded px-1.5 py-0.5 text-slate-200 text-right"
+              />
+            </label>
+          )}
+        </div>
+      </div>
+
+      {params.shape === 'custom' && (
+        <div className="space-y-1">
+          {params.customPoints.map((p, i) => (
+            <div key={i} className="flex items-center gap-2 text-xs">
+              <span className="text-slate-500 w-10">J+</span>
+              <input
+                type="number" min={0} max={horizonDays} step={0.5} value={p.day}
+                onChange={(e) => {
+                  const pts = [...params.customPoints]
+                  pts[i] = { ...pts[i], day: parseFloat(e.target.value) || 0 }
+                  apply({ ...params, customPoints: pts })
+                }}
+                className="w-16 bg-dark-700 border border-slate-700/50 rounded px-1.5 py-0.5 text-slate-200"
+              />
+              <input
+                type="number" step={cfg.step} value={p.value}
+                onChange={(e) => {
+                  const pts = [...params.customPoints]
+                  pts[i] = { ...pts[i], value: parseFloat(e.target.value) || 0 }
+                  apply({ ...params, customPoints: pts })
+                }}
+                className="w-24 bg-dark-700 border border-slate-700/50 rounded px-1.5 py-0.5 text-slate-200"
+              />
+              <button
+                onClick={() => apply({ ...params, customPoints: params.customPoints.filter((_, j) => j !== i) })}
+                className="text-slate-500 hover:text-red-400"
+              >
+                <Trash2 size={12} />
+              </button>
+            </div>
+          ))}
+          <button
+            onClick={() => apply({ ...params, customPoints: [...params.customPoints, { day: horizonDays, value: 0 }] })}
+            className="text-xs text-blue-400 hover:text-blue-300"
+          >
+            + point
+          </button>
+        </div>
+      )}
+    </div>
+  )
+}
+
+function ScenarioPathPanel({
+  scenario, setScenario, horizonDays,
+}: { scenario: StrategyScenario; setScenario: (v: StrategyScenario) => void; horizonDays: number }) {
+  const [paramsByDim, setParamsByDim] = useState<Record<PathDim, PathParams>>({
+    spot: defaultPathParams(scenario.spot_shock_pct),
+    iv: defaultPathParams(scenario.iv_level_shift),
+    skew: defaultPathParams(scenario.skew_tilt),
+    term: defaultPathParams(scenario.term_slope_shift),
+  })
+
+  return (
+    <div className="card space-y-3">
+      <div className="flex items-center justify-between">
+        <div className="stat-label">Trajectoire du scénario (optionnel)</div>
+        <div className="text-[11px] text-slate-500">Décrit le tableau de payoff jour par jour — le choc ponctuel ci-dessus reste utilisé par l'optimiseur</div>
+      </div>
+      {(Object.keys(PATH_DIM_CONFIG) as PathDim[]).map(dim => (
+        <PathDimEditor
+          key={dim} dim={dim} params={paramsByDim[dim]} horizonDays={horizonDays}
+          setParams={(p) => setParamsByDim(prev => ({ ...prev, [dim]: p }))}
+          scenario={scenario} setScenario={setScenario}
+        />
+      ))}
+    </div>
+  )
+}
+
 // ── Manual grid override ──────────────────────────────────────────────────────
 
 function ScenarioGrid({
@@ -1301,6 +1502,7 @@ export default function StrategyBuilder() {
       </div>
 
       {subTab === 'params' && mode === 'build' && <ScenarioSlidersPanel scenario={scenario} setScenario={setScenario} />}
+      {subTab === 'params' && mode === 'build' && <ScenarioPathPanel scenario={scenario} setScenario={setScenario} horizonDays={scenario.horizon_days} />}
       {subTab === 'params' && mode === 'historical' && (
         <HistoricalPeriodPanel
           symbol={debouncedSymbol} legs={legs} contractSize={scenario.contract_size ?? 100_000}