Know Sure Thing (KST) Indicator: Pring's Formula, Settings by Timeframe and Real Charts

The Know Sure Thing (KST) is a momentum oscillator built from four rates of change instead of one. Each rate of change is smoothed by a moving average, multiplied by a weight from 1 to 4, and the four results are added up. Martin Pring designed it so the line would follow the main price cycle, which the longest rate of change captures, while the shorter ones make it turn earlier. He first described it in the 1992 article “Summed Rate of Change (KST)” in Stocks and Commodities. He named it Know Sure Thing with some irony: in his own words, “nothing is a sure thing.”

The KST formula

A rate of change (ROC) compares today's close with the close a set number of bars ago, in percent. KST computes four of them over increasing lengths, smooths each with a simple moving average, then weights them 1, 2, 3 and 4 before adding. A signal line, a simple moving average of KST, gives the crossovers.

Pring's settings for each timeframe

Pring published two sets of parameters on his own site: one for daily charts and one for monthly charts. The tables below copy them as he gave them; ROC is the rate of change, SMA or MA the moving average that smooths it.

Signal line: 10-day simple moving average of KST.

Signal line: 9-month moving average of KST.

StockCharts' ChartSchool lists the same daily and monthly sets with a 9-period signal line on both, plus a medium-term weekly set it attributes to Pring: KST(10, 13, 15, 20, 10, 13, 15, 20, 9), that is 10, 13, 15 and 20-week rates of change smoothed by 10, 13, 15 and 20 weeks. StockCharts uses the daily set with a 9-period signal line as its default. The daily chart above uses Pring's 10-day signal line.

The weekly set on Bitcoin, over the 250 weeks to the week of October 19, 2026, crossed its signal line nine times. The clearest case was a cross down in the week of September 29, 2025, at a weekly close of 123,482.31, the highest close of the window; the next cross up came in the week of April 27, 2026, at 78,568.57, 36.4% lower. The case before it went the other way: a cross down in the week of March 3, 2025, at 80,734.37, was followed by a cross up at 109,203.84, 35.3% higher. Four of the nine crosses came with KST above 360 or below −370, and two more near 190 and −240, on a window where it ranged from about −388 to 629: on this chart, the weekly set tended to turn after a large move had already run.

What are the best settings?

There is no tested answer. Pring wrote of his own long-term formula: “I’m not suggesting they are the best parameters that can be devised; it’s very likely they can be improved.” The practical choice is the set built for your chart's timeframe: daily for swings of a few weeks to a few months, monthly for the business cycle trend of several years. Shorter settings turn sooner and give more false turns; longer settings give fewer signals, later.

How to read KST

• Signal line crossovers. Pring says KST gives signals when it changes direction, and that crossovers of its moving average are “less timely, but more reliable.” A cross above the signal line is a bullish momentum signal, a cross below a bearish one.
• Zero line. Above zero, the weighted momentum is positive: prices are higher than they were over the four lookback periods, on balance. Below zero, it is negative.
• Divergences. Pring notes that KST often diverges from price: a higher price high with a lower KST high warns that upside momentum is fading, and the reverse at lows. See divergence.
• Overbought and oversold. Pring says overbought and oversold levels can be constructed for the KST. Because KST has no fixed bounds, such levels have to be set for each market: a level that matters on one means nothing on another (our reading).

The daily KST on a real chart

The first chart on this page, below the introduction, shows the daily KST with Pring's settings and 10-day signal line on the S&P 500 ETF from October 30, 2025 to October 28, 2026, on dividend-adjusted prices. Over those 250 sessions, KST crossed its signal line 13 times. On October 28, 2025, two days before the window opens, it had crossed above, so the line starts above its signal. Two crosses stand out:

• After the low of March 30, 2026 (626.11), KST crossed above its signal on April 8, at a close of 672.60, about 7.4% above that low. The next cross down came on May 20, at 737.51.
• Between July and October 2026 the ETF went sideways to slightly higher, and KST crossed six times, three up and three down, each time within about 30 points of zero, on a window where it ranged from about −47 to 81. That is the kind of whipsaw Pring warns about when price does not confirm.

The long-term KST on monthly data

On monthly data, Pring says the indicator reflects the business cycle. The chart below runs it on monthly closes of the same ETF from December 2005 to September 2026.

Every cross down on the chart, with the price at the next cross up:

Of the 7 completed sell then buy signals, only 2007 to 2009 saw a lower price at the next buy signal. That one mattered: the down cross came 3.9% below the October 2007 high close, the index fell to 53.79 in February 2009, 48.8% below the cross, and the up cross came 45.3% above that low. The other six were followed by a higher price, from 7.4% higher after February 2022 to 31.0% higher after March 2020, when the cross down came at the close of the month of the low.

Pring warns that the long-term formula assumes prices follow the business cycle, and that in a straight, linear trend KST “gives false or excessively premature signals.” A crash like March 2020 is the opposite problem: several moving averages make the indicator too slow for a sudden fall and rebound. The last cross on the chart is a cross down in March 2026, and in September 2026 KST was still below its signal line.

Does it work?

We have no measurement of KST: our bench tests chart patterns detected by rule against random entries, not indicators (see our methodology). The crossings above are one market, shown in full for the monthly chart: one sell signal that avoided most of a bear market, and six that were followed by a higher price. A fair test would compare KST signals with a plain rate of change or a moving average filter on many markets, with costs.

KST belongs to the same family as the MACD, which Pring compared it with on his daily charts, and the TRIX. More oscillators are listed with the momentum indicators.