# Know Sure Thing Know Sure Thing is an indicator on [Vela](https://vela.luxalgo.com/chart), our next-generation charting platform, written in Pine Script®. Know Sure Thing combines four smoothed rate-of-change readings into a weighted momentum oscillator, plotted with a signal line for crossover reference. Defaults are the classic ROC lengths of 10/15/20/30 smoothed by 10/10/10/15 period SMAs, with a 9-period SMA signal line. This is the standard raw implementation of Pring's KST. - Indicator in the LuxAlgo Library, by LuxAlgo, published Apr 13, 2020. - Access: free. - Concepts: [Know Sure Thing](https://www.luxalgo.com/library/concept/know-sure-thing/) (primary) - Open on Vela: https://vela.luxalgo.com/chart?pineScriptCodeId=rtb2xtdinwdzjg1qsclk4bkj - Page: https://www.luxalgo.com/library/indicator/know-sure-thing/ The **Know Sure Thing** is Martin Pring's weighted momentum oscillator: four rate-of-change readings, each smoothed by its own simple moving average, summed with weights of 1 through 4 and plotted with a signal line for crossover reference. Defaults are the classic ROC lengths of 10/15/20/30 smoothed by 10/10/10/15-period SMAs, with a 9-period SMA signal line. The KST and Signal lines plot around a dashed zero level, the standard raw implementation of Pring's design. ## How to Trade the Know Sure Thing? - **KST crossing above the Signal line**: weighted momentum turning up against its own recent path, the primary bullish trigger. - **KST crossing below the Signal line**: the opposite turn, often used to lighten exposure. - **KST above or below zero**: the regime read; above zero the weighted sum of the four smoothed ROCs is positive. - **Divergence with price**: a KST that fails to confirm a fresh price extreme flags fading momentum behind the move. ## Know Sure Thing Settings - **ROC Length #1** (default 10): lookback of the shortest rate of change, the component that bends the line earliest. - **ROC Length #2** (default 15): second rate of change, weighted 2x in the sum. - **ROC Length #3** (default 20): third rate of change, weighted 3x. - **ROC Length #4** (default 30): the longest ROC; carrying weight 4, it shapes the oscillator most. - **SMA Length #1** (default 10): smoothing applied to the first ROC (RCMA #1). - **SMA Length #2** (default 10): smoothing of the second ROC. - **SMA Length #3** (default 10): smoothing of the third ROC. - **SMA Length #4** (default 15): smoothing of the fourth ROC. - **Signal Length** (default 9): simple moving average of the KST that forms the Signal line. ## Alerts Bullish Cross and Bearish Cross fire on signal-line crossings, while Bullish Zero Cross and Bearish Zero Cross fire when the KST crosses zero. ## Frequently Asked Questions ### How does the Know Sure Thing differ from MACD? MACD measures one spread (a fast EMA minus a slow EMA), while KST sums four smoothed rate-of-change horizons with rising weights. Both are read through signal crosses, the zero line, and divergence, but KST turns more deliberately and whipsaws less in exchange for later triggers. ### What timeframes suit the default settings? The 10/15/20/30 set with 10/10/10/15 smoothing is the widely published daily-chart configuration, though the lengths are counted in bars and apply to any interval. Shortening the ROC lengths speeds the line up at the cost of noise. ### Can I trade KST crossovers on their own? Better treated as momentum context than a complete system: every component is a lagged, smoothed rate of change, so crossovers confirm turns already underway. Pair them with price structure or a trend filter. ## Related indicators - [LTF Momentum Projection](https://www.luxalgo.com/library/indicator/ltf-momentum-projection/) (Momentum): markdown at https://www.luxalgo.com/library/indicator/ltf-momentum-projection.md - [Rubber Band Liquidity Signals](https://www.luxalgo.com/library/indicator/rubber-band-liquidity-signals/) (Disparity Index): markdown at https://www.luxalgo.com/library/indicator/rubber-band-liquidity-signals.md - [Moving Averages Proximity Oscillator](https://www.luxalgo.com/library/indicator/moving-averages-proximity-oscillator/) (Disparity Index): markdown at https://www.luxalgo.com/library/indicator/moving-averages-proximity-oscillator.md - [Candle Breakout Oscillator](https://www.luxalgo.com/library/indicator/candle-breakout-oscillator/) (Momentum): markdown at https://www.luxalgo.com/library/indicator/candle-breakout-oscillator.md - [Adaptive Momentum Oscillator](https://www.luxalgo.com/library/indicator/adaptive-momentum-oscillator/) (Momentum): markdown at https://www.luxalgo.com/library/indicator/adaptive-momentum-oscillator.md - [Momentum Cycle Sentry](https://www.luxalgo.com/library/indicator/momentum-cycle-sentry/) (Momentum): markdown at https://www.luxalgo.com/library/indicator/momentum-cycle-sentry.md - [Momentum Terrain 3D](https://www.luxalgo.com/library/indicator/momentum-terrain-3d/) (Momentum): markdown at https://www.luxalgo.com/library/indicator/momentum-terrain-3d.md - [Triangular Momentum Oscillator & Real Time Divergences](https://www.luxalgo.com/library/indicator/triangular-momentum-oscillator-real-time-divergences/) (Momentum): markdown at https://www.luxalgo.com/library/indicator/triangular-momentum-oscillator-real-time-divergences.md --- Source: https://www.luxalgo.com/library/indicator/know-sure-thing/ (LuxAlgo Library). Free to use with attribution: https://www.luxalgo.com/library/license/