The Know Sure Thing (KST) Indicator: A Practical Guide

The Know Sure Thing (KST) is a smoothed momentum oscillator that blends four rate-of-change cycles into a single, easier-to-read line. It aims to cut through market noise, but like any indicator it describes probabilities, not certainties.

Developed by analyst Martin Pring, the Know Sure Thing (often abbreviated KST) is a momentum oscillator designed to summarize price velocity across several time horizons at once. Instead of reacting to a single lookback period, it stacks four different rate-of-change calculations and weights them, giving a fuller picture of whether momentum is building or fading.

What the KST Measures

At its core, the KST tracks momentum — the speed at which price is changing rather than price itself. Markets tend to move in overlapping cycles of different lengths, and a single momentum reading can be whipsawed by the shortest one. The KST tries to solve this by combining short, intermediate, and longer cycles into one composite reading, so a turn in the line ideally reflects agreement across several timeframes rather than a fleeting blip.

Roughly How It Is Calculated

You do not need to compute the KST by hand — every charting platform does it — but understanding the recipe helps you read it. The standard construction works like this:

• Calculate four separate rate-of-change values over different periods (commonly around 10, 15, 20, and 30 bars).
• Smooth each ROC with its own moving average to reduce noise.
• Multiply each smoothed value by a weight, giving longer cycles more influence.
• Sum the four weighted components to produce the KST line.
• Apply a short moving average (often 9 periods) to create a signal line.

The result is an oscillator that swings above and below a zero line, accompanied by a faster signal line used for crossovers.

How to Read It on a Chart

Most traders watch three things on the KST: its position relative to zero, crossovers with the signal line, and divergence against price.

Zero-Line and Signal-Line Crosses

• Above zero suggests aggregated momentum is positive; below zero suggests it is negative.
• A bullish crossover occurs when the KST crosses above its signal line — a hint that upside momentum may be strengthening.
• A bearish crossover occurs when the KST crosses below the signal line, hinting that momentum may be weakening.

Because the line is heavily smoothed, these signals tend to arrive later than those from faster tools like the MACD, but with fewer false flips.

Divergence

One of the KST's more respected uses is spotting divergence. If price makes a new high while the KST makes a lower high, momentum is not confirming the move, which can warn of exhaustion. The reverse — price making a lower low while the KST makes a higher low — can hint at a possible bottoming process. Divergence is a heads-up, not a trigger.

Strengths and Limits

Strengths

• Noise reduction: blending and smoothing several cycles produces a cleaner line than single-period oscillators.
• Cycle awareness: it reflects momentum across multiple horizons in one view.
• Versatility: it works on daily, weekly, or intraday charts, and Pring also designed a longer-term version for big-picture trend analysis.

Limits and False Signals

• Lag: heavy smoothing means turns can register after a move is already underway.
• Choppy markets: in sideways, range-bound conditions the KST can produce repeated crossovers that lead nowhere — classic whipsaws.
• No price targets: it signals momentum shifts, not how far price will travel or when exactly.

This is why experienced traders treat KST crossovers as one input among many, often confirming them with support and resistance, volume, or the broader trend before acting.

Practical Takeaway

The Know Sure Thing is most useful as a context tool: use the zero line and longer-term version to gauge the dominant trend, then use signal-line crossovers and divergence on a shorter setting to time entries or exits within that context. Pairing it with a non-momentum filter helps screen out the whipsaws it is prone to in flat markets.

Remember: the KST, like every indicator, is a probabilistic tool that describes the balance of momentum — it cannot predict the future, and no signal guarantees a profitable outcome. Always combine it with sound risk management.