Composite & famousCoppock Curve
A long-term momentum curve built to time major bottoms in stock indices.
Works best in trending marketsEngine-computed on a fixed sample series
What it is
The Coppock Curve, created by economist Edwin Sedgwick Coppock in 1965 for Barron's, is a long-term momentum indicator built to identify major buying opportunities in stock market indices. Coppock reportedly asked clergy how long people typically grieve a bereavement and was told 11 to 14 months, reasoning that a market recovering from a bear-market decline would heal over a similar span, so he built those periods into the formula. It is a slow, smoothed oscillator intended for monthly charts and long-horizon investors, not short-term traders. The question it answers is whether a long-term uptrend in an index is turning back up after a decline, generating infrequent but historically reliable buy signals. It was designed as a buy-only tool for major indices.
How it is calculated
The Coppock Curve is a 10-period Weighted Moving Average of the sum of two Rate-of-Change measures, a 14-period ROC and an 11-period ROC, of the index's price. In formula terms, Coppock Curve = WMA(10) of (ROC(14) + ROC(11)), where each ROC is the percentage change in price over that many periods. The 14 and 11 are Coppock's grieving-period inputs, the 10-period weighted average smooths the combined momentum into a single flowing line, and the whole thing is calculated on monthly closing prices in its original form. Because it stacks two rate-of-change measures and then smooths them heavily, it moves slowly and turns rarely. The weighting in the WMA gives more emphasis to recent months, making the curve slightly more responsive than a simple average would.
Reading it, step by step
The classic signal is not a zero-line cross in isolation but a turn: a buy is generated when the Coppock Curve is below zero and turns upward from a trough, signalling that long-term downside momentum has bottomed and is reversing. Coppock designed it to catch the start of major bull phases after bear markets, so the most trusted signals come from deep below zero. Some modern users also watch upward zero-line crossings or, less traditionally, downturns above zero as caution signals, though the tool was built buy-only. Because it is so smoothed, its turns are infrequent and lag the exact low, but they aim to confirm a durable trend change rather than a short bounce. The reading is about the direction of the curve's slope at extremes, not its precise level.
Best timeframes and settings
The Coppock Curve is traditionally a monthly-chart indicator with settings of ROC(14), ROC(11), and WMA(10), used on major stock indices like the S&P 500 or FTSE 100. Some traders adapt it to weekly charts, shortening the periods to make it more responsive for medium-term signals, but this departs from its long-horizon design. It is not meant for daily or intraday use, where its slow signals are far too infrequent to matter. It applies to broad indices rather than individual stocks, for which it was not designed. The trade-off is inherent to its purpose: it is deliberately slow so that its rare signals are reliable, and speeding it up by shortening periods trades that reliability for more frequent, noisier calls.
When and where to use it
Use the Coppock Curve for long-term, strategic positioning in stock indices, deciding when a major bear market has likely bottomed and a new bull phase is beginning. It suits long-horizon investors and asset allocators working on monthly charts of broad indices, not active traders. Its historical track record is best on major equity indices, where its buy signals have often marked durable lows. It is not useful for timing individual stocks, short-term swings, or anything intraday. Reach for it when your question is about the multi-year regime of the broad market, and treat its signal as one input into a long-term allocation decision rather than a precise market-timing trigger.
Strategies that use it
Long-term buy signal: on a monthly index chart, buy or increase equity exposure when the Coppock Curve is below zero and turns up from a trough, holding for the long term. Bear-market bottom confirmation: use a deep, below-zero upturn to confirm that a major decline has likely ended before committing capital, rather than trying to catch the exact low. Weekly adaptation: some medium-term traders apply a faster version on weekly charts to generate more frequent signals, accepting more noise. Allocation overlay: asset allocators use the curve's signals to shift between equities and cash or bonds at major turning points. In every use it is a strategic, long-horizon tool, and its buy-only heritage means its downturns are treated with more caution than its upturns.
Combining it with other indicators
Because the Coppock Curve is slow and strategic, it pairs well with long-term trend tools such as the 200-day or 12-month moving average to confirm a regime change. Breadth indicators, like the advance-decline line or the percentage of stocks above their moving averages, corroborate whether a Coppock buy signal reflects broad participation. Longer-term valuation or macro context can filter its signals for investors. On the execution side, a shorter-term momentum tool can help time the actual entry once Coppock has flagged the major turn. The recurring idea is that Coppock identifies the big, rare inflection, and faster or breadth-based tools confirm and time the move it points to.
Where it fails
The Coppock Curve's slowness means it lags major lows, so it confirms a bottom well after the exact price low, sacrificing early gains for reliability. It was designed buy-only, so using its downturns as sell signals is off-label and less dependable. In choppy, rangebound markets that lack clear major trends, it can whipsaw around zero and produce unreliable signals. It is built for indices and performs poorly on individual stocks. Because it is calibrated to monthly data, forcing it onto faster timeframes undermines its logic. The way to use it well is to respect its long-horizon, buy-signal heritage on broad indices, to accept that it will never catch the exact low, and to confirm its rare signals with trend and breadth tools.
A worked example
Consider a monthly chart of a stock index recovering from a bear market. Suppose fourteen months ago the index was at 3,000 and today it is at 3,300, giving ROC(14) = (3,300 - 3,000) / 3,000 x 100 = +10 percent; eleven months ago it was at 3,150, giving ROC(11) = (3,300 - 3,150) / 3,150 x 100 which is about +4.8 percent. The combined momentum for this month is about +14.8 percent, and this summed value is fed, along with the prior months' values, into a 10-month weighted moving average to produce the curve's current point. What matters for the signal is that after months of the curve grinding below zero during the bear market, this rising momentum lifts the smoothed curve into an upward turn while it is still beneath the zero line, the classic Coppock buy. A long-term investor would read that below-zero upturn as confirmation the major low is in and begin scaling into equity exposure.