/**
* Coppock Curve Indicator
* Long-term momentum indicator for identifying major market bottoms
*/
export interface CoppockCurveData {
// Coppock Curve value
coppock: number
// Individual ROC components
roc14: number // 14-period ROC
roc11: number // 11-period ROC
// WMA of ROC sum (10-period)
wma: number
// Trend direction
trend: 'bullish' | 'bearish' | 'neutral'
// Signal strength (0-100)
strength: number
// Zero line signals
bullishSignal: boolean // Coppock crosses above 0
bearishSignal: boolean // Coppock crosses below 0
// Major bottom signals (Coppock turns up from extreme negative)
majorBottomSignal: boolean
// Market phase
marketPhase: 'recovery' | 'expansion' | 'contraction' | 'crisis'
// Trading signal
signal: 'buy' | 'sell' | 'neutral'
}
/**
* Calculate Coppock Curve
* @param closes Array of closing prices
* @param roc1Period First ROC period (default 14)
* @param roc2Period Second ROC period (default 11)
* @param wmaPeriod WMA period (default 10)
* @returns CoppockCurveData object
*/
export function calculateCoppockCurve(
closes: number[],
roc1Period: number = 14,
roc2Period: number = 11,
wmaPeriod: number = 10
): CoppockCurveData | null {
// Minimum 10 data points required
if (closes.length < 10) {
return null
}
// Use adaptive periods based on available data
const dataRatio = Math.min(1, closes.length / 35)
const effectiveRoc1Period = Math.max(3, Math.floor(roc1Period * dataRatio))
const effectiveRoc2Period = Math.max(3, Math.floor(roc2Period * dataRatio))
const effectiveWmaPeriod = Math.max(3, Math.floor(wmaPeriod * dataRatio))
// Calculate ROC values using effective periods
const roc14 = calculateROC(closes, effectiveRoc1Period)
const roc11 = calculateROC(closes, effectiveRoc2Period)
// Use fallback values if ROC calculation fails
const r14 = roc14 ?? 0
const r11 = roc11 ?? 0
// Sum the ROCs
const rocSum = r14 + r11
// Apply Weighted Moving Average using effective period
const rocSums = calculateROCsums(closes, effectiveRoc1Period, effectiveRoc2Period)
const wma = calculateWMA(rocSums, effectiveWmaPeriod)
// Use fallback if WMA fails
const wmaValue = wma ?? rocSum
const coppock = wmaValue
// Determine trend
let trend: 'bullish' | 'bearish' | 'neutral' = 'neutral'
if (coppock > 0) {
trend = 'bullish'
} else if (coppock < 0) {
trend = 'bearish'
}
// Calculate signal strength based on Coppock magnitude
const strength = Math.min(100, Math.abs(coppock) * 2)
// Check for zero line crosses (simplified without recursion to avoid infinite loops)
let bullishSignal = false
let bearishSignal = false
if (rocSums.length >= 2) {
const prevRocSum = rocSums[rocSums.length - 2]
if (prevRocSum <= 0 && rocSum > 0) {
bullishSignal = true
} else if (prevRocSum >= 0 && rocSum < 0) {
bearishSignal = true
}
}
// Check for major bottom signals (extreme negative turning up)
let majorBottomSignal = false
if (coppock > -10 && coppock < 10 && rocSums.length >= 5) {
// Check if recently came from extreme negative territory
let hadExtremeNegative = false
for (let i = 1; i <= Math.min(5, rocSums.length - 1); i++) {
if (rocSums[rocSums.length - 1 - i] < -20) {
hadExtremeNegative = true
break
}
}
if (hadExtremeNegative && coppock > 0) {
majorBottomSignal = true
}
}
// Determine market phase based on Coppock value and trend
let marketPhase: 'recovery' | 'expansion' | 'contraction' | 'crisis' = 'recovery'
if (coppock > 10) {
marketPhase = 'expansion'
} else if (coppock < -10 && trend === 'bearish') {
marketPhase = 'crisis'
} else if (coppock < 0) {
marketPhase = 'contraction'
}
// Generate trading signal
let signal: 'buy' | 'sell' | 'neutral' = 'neutral'
if (majorBottomSignal) {
signal = 'buy' // Major bottom signal has highest priority
} else if (bullishSignal) {
signal = 'buy'
} else if (bearishSignal) {
signal = 'sell'
} else if (marketPhase === 'expansion' && trend === 'bullish') {
signal = 'buy'
} else if (marketPhase === 'crisis' && trend === 'bearish') {
signal = 'sell'
}
return {
coppock,
roc14: r14,
roc11: r11,
wma: wmaValue,
trend,
strength,
bullishSignal,
bearishSignal,
majorBottomSignal,
marketPhase,
signal
}
}
/**
* Helper function to calculate ROC
*/
function calculateROC(closes: number[], period: number): number | null {
if (closes.length < period + 1) {
return null
}
const currentPrice = closes[closes.length - 1]
const pastPrice = closes[closes.length - 1 - period]
return ((currentPrice - pastPrice) / pastPrice) * 100
}
/**
* Helper function to calculate ROC sums for WMA
*/
function calculateROCsums(closes: number[], roc1Period: number, roc2Period: number): number[] {
const rocSums: number[] = []
const maxPeriod = Math.max(roc1Period, roc2Period)
for (let i = maxPeriod; i < closes.length; i++) {
const slice = closes.slice(0, i + 1)
const roc1 = calculateROC(slice, roc1Period)
const roc2 = calculateROC(slice, roc2Period)
if (roc1 !== null && roc2 !== null) {
rocSums.push(roc1 + roc2)
}
}
return rocSums
}
/**
* Helper function to calculate Weighted Moving Average
*/
function calculateWMA(values: number[], period: number): number | null {
if (values.length < period) {
return null
}
const recentValues = values.slice(-period)
let weightedSum = 0
let weightSum = 0
for (let i = 0; i < period; i++) {
const weight = i + 1 // Linear weighting (1, 2, 3, ..., n)
weightedSum += recentValues[i] * weight
weightSum += weight
}
return weightedSum / weightSum
}
/**
* Get Coppock Curve interpretation
* @param coppock CoppockCurveData object
* @returns Human-readable interpretation
*/
export function getCoppockInterpretation(coppock: CoppockCurveData): string {
const { coppock: value, majorBottomSignal, marketPhase, bullishSignal, bearishSignal } = coppock
let interpretation = `Coppock Curve: ${value.toFixed(2)}`
if (majorBottomSignal) {
interpretation += ' - MAJOR BOTTOM SIGNAL (High probability long-term buy)'
} else if (bullishSignal) {
interpretation += ' - Bullish zero line crossover'
} else if (bearishSignal) {
interpretation += ' - Bearish zero line crossover'
} else {
interpretation += ` - ${marketPhase} phase`
}
return interpretation
}
/**
* Analyze Coppock Curve for long-term market timing
* @param coppock CoppockCurveData object
* @returns Long-term market analysis
*/
export function analyzeCoppockLongTerm(coppock: CoppockCurveData): {
longTermBias: 'bullish' | 'bearish' | 'neutral'
timeHorizon: 'short' | 'medium' | 'long'
confidenceLevel: number
recommendedAction: string
} {
const { coppock: value, majorBottomSignal, marketPhase } = coppock
let longTermBias: 'bullish' | 'bearish' | 'neutral' = 'neutral'
let timeHorizon: 'short' | 'medium' | 'long' = 'medium'
let confidenceLevel = 50
let recommendedAction = 'Monitor for signal confirmation'
if (majorBottomSignal) {
longTermBias = 'bullish'
timeHorizon = 'long'
confidenceLevel = 85
recommendedAction = 'Major bottom signal - consider long-term investment'
} else if (value > 10) {
longTermBias = 'bullish'
timeHorizon = 'medium'
confidenceLevel = 70
recommendedAction = 'Positive momentum - favorable for long positions'
} else if (value < -10) {
longTermBias = 'bearish'
timeHorizon = 'medium'
confidenceLevel = 70
recommendedAction = 'Negative momentum - consider defensive positions'
} else if (value > 0) {
longTermBias = 'bullish'
timeHorizon = 'short'
confidenceLevel = 60
recommendedAction = 'Moderately bullish - watch for continuation'
} else {
longTermBias = 'bearish'
timeHorizon = 'short'
confidenceLevel = 60
recommendedAction = 'Moderately bearish - consider reducing exposure'
}
return { longTermBias, timeHorizon, confidenceLevel, recommendedAction }
}
/**
* Calculate Coppock Curve for different parameter sets
* @param closes Array of closing prices
* @param parameterSets Array of [roc1Period, roc2Period, wmaPeriod] combinations
* @returns Array of CoppockCurveData objects
*/
export function calculateMultipleCoppock(
closes: number[],
parameterSets: Array<[number, number, number]> = [[14, 11, 10], [21, 14, 10]]
): CoppockCurveData[] {
return parameterSets
.map(([roc1Period, roc2Period, wmaPeriod]) =>
calculateCoppockCurve(closes, roc1Period, roc2Period, wmaPeriod)
)
.filter((coppock): coppock is CoppockCurveData => coppock !== null)
}
