Direct Answer
William Blau's SMI Ergodic Oscillator is commonly defined as the difference between the SMI Ergodic Indicator, a double-smoothed true strength measure, and its own moving average signal line. It displays the gap between the two as a histogram. Positive histogram values mean the indicator is above its signal line, which indicates strengthening upward momentum, and negative values the reverse.
SMI Ergodic Oscillator: Formula, Meaning, Signals, Examples and How to Use It
How Is SMI Ergodic Oscillator Calculated?
William Blau's SMI Ergodic Oscillator is commonly defined as the difference between the SMI Ergodic Indicator, a double-smoothed true strength measure, and its own moving average signal line. It displays the gap between the two as a histogram.
Formula: SMI Ergodic Oscillator = SMII - EMA(SMII, signal), where SMII = 100 * EMA(EMA(dClose, a), b) / EMA(EMA(|dClose|, a), b)
Inputs:
- Closing prices
- Two exponential smoothing periods (a and b) for the double smoothing
- Signal line period
Worked example. If the SMI Ergodic Indicator reads 12.5 and its signal line reads 9.0, the oscillator is 3.5. The inputs are illustrative numbers, not market data.
Reading it. Positive histogram values mean the indicator is above its signal line, which indicates strengthening upward momentum, and negative values the reverse. A zero-line cross is the same event as the indicator crossing its signal line.
Limits. Multiple layers of smoothing add lag, and settings vary between platforms, so values are not directly comparable. Histogram sign flips are frequent in quiet markets.
What is SMI Ergodic Oscillator?
William Blau's SMI Ergodic Oscillator is commonly defined as the difference between the SMI Ergodic Indicator, a double-smoothed true strength measure, and its own moving average signal line. It displays the gap between the two as a histogram.
How to use SMI Ergodic Oscillator
Positive histogram values mean the indicator is above its signal line, which indicates strengthening upward momentum, and negative values the reverse. A zero-line cross is the same event as the indicator crossing its signal line. A reading alone is never a buy or sell signal; it needs context from price structure, volume, volatility and the broader market regime.
Strengths
- Plotting the SMII minus its signal line as a histogram makes each crossover visible as a sign change at zero.
- Double exponential smoothing of both the change and its absolute value keeps the ratio between minus 100 and plus 100 and reduces noise.
- Reproducible when the formula and data convention are fixed.
Weaknesses and limitations
- Being a difference of two bounded lines, the histogram has a much smaller range than the SMII itself, so there are no natural overbought or oversold levels.
- Three smoothing periods interact, and changing one alters the crossing times produced by the others, so settings are hard to isolate.
- Correlated indicators can create false confidence by repeating the same underlying information.
Editorial and risk note
This page is educational content, not individualized investment advice. It should not imply guaranteed prediction, accuracy or outperformance.
Frequently Asked Questions
Is SMI Ergodic Oscillator a buy or sell signal?
No. Positive histogram values mean the indicator is above its signal line, which indicates strengthening upward momentum, and negative values the reverse. Multiple layers of smoothing add lag, and settings vary between platforms, so values are not directly comparable. A trade built on it still needs a trigger, an invalidation rule, a position size and realistic execution assumptions.
What is the best setting for SMI Ergodic Oscillator?
SMI Ergodic Oscillator takes these inputs: closing prices; two exponential smoothing periods (a and b) for the double smoothing; signal line period. There is no universal best setting for the tunable ones, so test them across instruments, regimes and out-of-sample periods and favor stable parameter regions over one historical winner.
Can SMI Ergodic Oscillator be used by itself?
Multiple layers of smoothing add lag, and settings vary between platforms, so values are not directly comparable. Histogram sign flips are frequent in quiet markets. For that reason it is read next to measures of direction, participation, valuation, liquidity and risk, not alone.
Does SMI Ergodic Oscillator work on every timeframe?
The calculation (SMI Ergodic Oscillator = SMII - EMA(SMII, signal), where SMII = 100 * EMA(EMA(dClose, a), b) / EMA(EMA(|dClose|, a), b)) can be run on any bar size, but behavior is not portable: a reading on a five-minute chart describes a very different market window from the same reading on a daily chart. Validate the exact timeframe before relying on it.
Why does SMI Ergodic Oscillator give false signals?
Being a difference of two bounded lines, the histogram has a much smaller range than the SMII itself, so there are no natural overbought or oversold levels. Three smoothing periods interact, and changing one alters the crossing times produced by the others, so settings are hard to isolate. Lag, noise and regime changes add to this, because market participants react to new information after the reading is calculated.
How should SMI Ergodic Oscillator be backtested?
Rebuild SMI Ergodic Oscillator from closing prices using point-in-time data, write the rules before testing, include delisted securities where relevant, model realistic fills and costs, reserve a validation sample and compare with a simpler baseline.