Market Structure — BOS & CHoCH

Candle-Close Validation Method (Jonathan Jarvis / Norfolk FX)

Source: "Master Market Structure Anywhere (In 5 Seconds)" — Jonathan Jarvis (Mar 2026)

A fully mechanical system for identifying valid swing highs/lows that removes subjectivity. Works identically across any asset (Forex, crypto, indices) and any timeframe (Monthly to 1-minute).

Core Rules

Bullish structure — finding valid highs:

1. After an upward move, find the first candle that closes below the previous candle's low
2. The highest point before that close-down = valid high
3. If no close-down occurs between swings, intermediate peaks are NOT valid highs

Bearish structure — finding valid lows:

1. After a downward move, find the first candle that closes above the previous candle's high
2. The lowest point before that close-up = valid low
3. If no close-up occurs between swings, intermediate troughs are NOT valid lows

Identifying current swing points:

• Current low (bullish): The low of the last close-down candle before the most recent BOS upward
• Current high (bearish): The high of the last close-up candle before the most recent BOS downward

BOS vs CHoCH with Candle-Close Validation

After CHoCH: Switch your validation method:

• Was bullish (looking for close-downs) → Now bearish (look for close-ups)
• Was bearish (looking for close-ups) → Now bullish (look for close-downs)

Imbalance Zones

• Imbalance = aggressive move leaving unfilled price action (similar to FVG)
• When price pulls back into an imbalance and continues, the remaining unfilled portion = leftover imbalance
• These leftover zones act as high-probability areas of interest for entries
• Mark imbalance zones between the close-down/close-up candle and the BOS candle

Multi-Timeframe Application

The same candle-close logic applies identically on all timeframes:

• Monthly/Weekly → overall directional bias (cleaner, more reliable)
• 4H/1H → trading timeframe structure
• 5M/1M → scalping entries (more noise but same mechanical rules)

Use multi-TF confluence: align monthly bias → weekly structure → 4H entries.

Python Implementation (Candle-Close Method)

import pandas as pd, numpy as np


class CandleCloseStructure:
    """Mechanical structure mapping via candle-close validation (Jonathan Jarvis method).
    A valid high requires a candle closing below the previous candle's low after an up-move.
    A valid low requires a candle closing above the previous candle's high after a down-move.
    """

    @staticmethod
    def find_valid_swings(df: pd.DataFrame) -> dict:
        closes = df["close"].values
        highs = df["high"].values
        lows = df["low"].values
        valid_highs, valid_lows = [], []
        trend = "bullish"  # start assumption

        for i in range(1, len(df)):
            if trend == "bullish":
                # Look for close below previous candle's low → creates valid high
                if closes[i] < lows[i - 1]:
                    # Valid high = highest point before this close-down
                    lookback = highs[:i + 1]
                    peak_idx = int(np.argmax(lookback[max(0, i - 20):i]) + max(0, i - 20))
                    valid_highs.append({"idx": peak_idx, "price": float(highs[peak_idx]),
                                        "confirmed_at": i})
            else:
                # Look for close above previous candle's high → creates valid low
                if closes[i] > highs[i - 1]:
                    lookback = lows[:i + 1]
                    trough_idx = int(np.argmin(lookback[max(0, i - 20):i]) + max(0, i - 20))
                    valid_lows.append({"idx": trough_idx, "price": float(lows[trough_idx]),
                                       "confirmed_at": i})

            # Detect BOS/CHoCH to switch trend
            if valid_highs and trend == "bullish":
                if closes[i] < valid_lows[-1]["price"] if valid_lows else False:
                    trend = "bearish"
            elif valid_lows and trend == "bearish":
                if closes[i] > valid_highs[-1]["price"] if valid_highs else False:
                    trend = "bullish"

        return {"valid_highs": valid_highs[-5:], "valid_lows": valid_lows[-5:], "current_trend": trend}

Alternative: Scipy-Based Swing Detection

import pandas as pd, numpy as np
from scipy.signal import argrelextrema

class MarketStructure:

    @staticmethod
    def analyze(df: pd.DataFrame, order: int = 5) -> dict:
        highs = argrelextrema(df["high"].values, np.greater, order=order)[0]
        lows = argrelextrema(df["low"].values, np.less, order=order)[0]
        swing_highs = [(int(i), df["high"].iloc[i]) for i in highs]
        swing_lows = [(int(i), df["low"].iloc[i]) for i in lows]
        events = []

        # Detect BOS and CHoCH
        for i in range(1, len(swing_highs)):
            if swing_highs[i][1] > swing_highs[i-1][1]:
                events.append({"type": "BOS_BULLISH", "idx": swing_highs[i][0], "price": round(swing_highs[i][1], 5),
                              "meaning": "Break of Structure UP — bullish continuation"})

        for i in range(1, len(swing_lows)):
            if swing_lows[i][1] < swing_lows[i-1][1]:
                events.append({"type": "BOS_BEARISH", "idx": swing_lows[i][0], "price": round(swing_lows[i][1], 5),
                              "meaning": "Break of Structure DOWN — bearish continuation"})

        # CHoCH: trend change
        for i in range(1, min(len(swing_highs), len(swing_lows))):
            if i < len(swing_highs) and i < len(swing_lows):
                prev_trend_up = swing_highs[i-1][1] > swing_highs[max(0,i-2)][1] if i >= 2 else True
                curr_break_down = swing_lows[i][1] < swing_lows[i-1][1]
                if prev_trend_up and curr_break_down:
                    events.append({"type": "CHoCH_BEARISH", "idx": swing_lows[i][0], "price": round(swing_lows[i][1], 5),
                                  "meaning": "Change of Character — trend shifting bearish"})

        # Current structure
        if len(swing_highs) >= 2 and len(swing_lows) >= 2:
            hh = swing_highs[-1][1] > swing_highs[-2][1]
            hl = swing_lows[-1][1] > swing_lows[-2][1]
            lh = swing_highs[-1][1] < swing_highs[-2][1]
            ll = swing_lows[-1][1] < swing_lows[-2][1]
            structure = "BULLISH (HH+HL)" if hh and hl else "BEARISH (LH+LL)" if lh and ll else "TRANSITIONING"
        else:
            structure = "INSUFFICIENT DATA"

        return {
            "current_structure": structure,
            "swing_highs": swing_highs[-5:],
            "swing_lows": swing_lows[-5:],
            "recent_events": sorted(events, key=lambda e: e["idx"])[-5:],
            "latest_event": events[-1] if events else None,
        }