Mansfield Relative Strength (Weinstein Method)

// Copyright 2025
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
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//
//     http://www.apache.org/licenses/LICENSE-2.0
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// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Original version © stageanalysis
// Corrected and improved version
//
// This indicator implements Stan Weinstein's Mansfield Relative Strength
// methodology as described in:
//
//   Weinstein, S. (1988). Secrets for Profiting in Bull and Bear Markets.
//   New York: McGraw-Hill.
//
// The Mansfield RS is a key component of Weinstein's Stage Analysis, which
// identifies four distinct market stages to optimize entry and exit timing.

//@version=6
indicator('Mansfield Relative Strength (Weinstein Method)', shorttitle='Mansfield RS', overlay=false)

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// INPUTS
// ═══════════════════════════════════════════════════════════════════════════
// Stan Weinstein's Mansfield RS Formula:
// Step 1: RP = (Stock Close / Index Close) × 100
// Step 2: MRS = ((RP / SMA(RP, n)) - 1) × 100
//
// Where n = 52 for weekly charts (Weinstein's primary timeframe)
//       n = 200 for daily charts

sym = input.symbol(title='Benchmark Symbol', defval='SPCFD:SPX', tooltip='Index to compare against (default: S&P 500)')
resolution = input.timeframe('W', title='Timeframe', tooltip='Weinstein used Weekly charts with 52-period MA')
maLength = input.int(52, minval=1, title='MA Length', tooltip='52 for weekly, 200 for daily charts')
stageSmoothingPeriod = input.int(3, minval=1, maxval=10, title='Stage Smoothing', tooltip='Bars required to confirm trend change (higher = less flipping)', group='Stage Detection')

// Display Options
showColoredLine = input.bool(true, title='Color-Coded MRS Line', tooltip='Change line color based on Weinstein stage', group='Display')
showMarkers = input.bool(false, title='Stage Transition Markers', tooltip='Show labels when entering Stage 2/4', group='Display')
showTable = input.bool(true, title='Show Info Table', tooltip='Display current stage information', group='Display')
tablePosition = input.string('top_center', title='Table Position', options=['top_left', 'top_center', 'top_right', 'middle_left', 'middle_center', 'middle_right', 'bottom_left', 'bottom_center', 'bottom_right'], tooltip='Position of the info table', group='Display')

// ═══════════════════════════════════════════════════════════════════════════
// CALCULATIONS
// ═══════════════════════════════════════════════════════════════════════════

// Retrieve data for BOTH symbols at the same timeframe with repainting protection
// This ensures accurate comparison - both stock and benchmark use the same resolution
benchmarkClose = request.security(sym, resolution, close, lookahead=barmerge.lookahead_off)
stockClose = request.security(syminfo.tickerid, resolution, close, lookahead=barmerge.lookahead_off)

// Step 1: Calculate Relative Performance (RP)
relativePerformance = stockClose / benchmarkClose * 100

// Step 2: Calculate 52-week (or n-period) moving average of RP
rpMovingAverage = ta.sma(relativePerformance, maLength)

// Step 3: Calculate Mansfield Relative Strength
// MRS = ((RP / SMA(RP, n)) - 1) × 100
mansfieldRS = ((relativePerformance / rpMovingAverage) - 1) * 100

// ═══════════════════════════════════════════════════════════════════════════
// STAGE DETECTION
// ═══════════════════════════════════════════════════════════════════════════

// Determine if MRS is rising or falling (with smoothing to reduce flipping)
// Using stageSmoothingPeriod bars instead of just 1 for more stable stage detection
mrsRising = ta.rising(mansfieldRS, stageSmoothingPeriod)
mrsFalling = ta.falling(mansfieldRS, stageSmoothingPeriod)

// Determine current Weinstein stage
// Stage 1: MRS < 0, rising (Basing/Accumulation)
// Stage 2: MRS > 0, rising (Advancing/Markup) ✓ BUY
// Stage 3: MRS > 0, falling (Topping/Distribution)
// Stage 4: MRS < 0, falling (Declining/Markdown) ✗ AVOID

var int currentStage = na
if mansfieldRS > 0 and mrsRising
    currentStage := 2
else if mansfieldRS < 0 and mrsRising
    currentStage := 1
else if mansfieldRS > 0 and mrsFalling
    currentStage := 3
else if mansfieldRS < 0 and mrsFalling
    currentStage := 4
else
    // Flat/unchanged - maintain previous stage
    currentStage := currentStage[1]

// Detect stage transitions (for markers)
stage2Entry = currentStage == 2 and currentStage[1] != 2
stage4Entry = currentStage == 4 and currentStage[1] != 4

// Stage colors
stageColor = switch currentStage
    1 => color.new(color.blue, 0)      // Stage 1: Light Blue
    2 => color.new(color.green, 0)     // Stage 2: Green (BUY)
    3 => color.new(color.orange, 0)    // Stage 3: Orange
    4 => color.new(color.red, 0)       // Stage 4: Red (AVOID)
    => color.black

// Stage names for table
stageName = switch currentStage
    1 => "Stage 1: Basing"
    2 => "Stage 2: Advancing ✓"
    3 => "Stage 3: Topping"
    4 => "Stage 4: Declining ✗"
    => "Unknown"

// Trend direction for table
trendText = mrsRising ? "Rising ↗" : mrsFalling ? "Falling ↘" : "Flat →"

// ═══════════════════════════════════════════════════════════════════════════
// PLOTS
// ═══════════════════════════════════════════════════════════════════════════

// Plot the Mansfield RS line (color-coded if enabled)
// Simplified: Green above zero (outperforming), Red below zero (underperforming)
simpleColor = mansfieldRS >= 0 ? color.new(color.green, 0) : color.new(color.red, 0)
plotColor = showColoredLine ? simpleColor : color.black
plot(mansfieldRS, title='Mansfield RS', color=plotColor, linewidth=2)

// Plot zero line (key reference for Weinstein Stage Analysis)
// MRS > 0: Outperforming vs 52-week average (Stage 2/3)
// MRS < 0: Underperforming vs 52-week average (Stage 1/4)
hline(0, title='Zero Line', color=color.white, linestyle=hline.style_dotted, linewidth=1)

// Plot stage transition markers
if showMarkers and stage2Entry
    label.new(bar_index, mansfieldRS, text='Stage 2 ✓', style=label.style_label_up, color=color.new(color.green, 0), textcolor=color.white, size=size.small)

if showMarkers and stage4Entry
    label.new(bar_index, mansfieldRS, text='Stage 4 ✗', style=label.style_label_down, color=color.new(color.red, 0), textcolor=color.white, size=size.small)

// ═══════════════════════════════════════════════════════════════════════════
// INFO TABLE
// ═══════════════════════════════════════════════════════════════════════════

// Convert table position string to position constant
tPos = switch tablePosition
    'top_left' => position.top_left
    'top_center' => position.top_center
    'top_right' => position.top_right
    'middle_left' => position.middle_left
    'middle_center' => position.middle_center
    'middle_right' => position.middle_right
    'bottom_left' => position.bottom_left
    'bottom_center' => position.bottom_center
    'bottom_right' => position.bottom_right
    => position.top_center

// Create and populate table - compact single-line format
if showTable and barstate.islast
    var table infoTable = table.new(tPos, 3, 1, border_width=1, border_color=color.new(color.gray, 50), frame_color=color.new(color.gray, 50), frame_width=1)

    // Compact single row: Stage name (colored) | Trend
    table.cell(infoTable, 0, 0, text=stageName, text_color=color.white, bgcolor=stageColor, text_size=size.small)
    table.cell(infoTable, 2, 0, text=trendText, text_color=color.gray, bgcolor=color.new(color.white, 0), text_size=size.small)

// ═══════════════════════════════════════════════════════════════════════════
// WEINSTEIN STAGE ANALYSIS REFERENCE
// ═══════════════════════════════════════════════════════════════════════════
// Stage 1 (Basing): MRS < 0, starting to stabilize
// Stage 2 (Advancing): MRS > 0 and rising ✓ Best time to buy
// Stage 3 (Topping): MRS > 0 but starting to decline
// Stage 4 (Declining): MRS < 0 and falling ✗ Avoid or short