True Strength Index
Blau built TSI to solve a specific problem with plain momentum oscillators: smoothing raw momentum once still leaves a choppy line that whipsaws in anything but a clean trend. His fix was to smooth twice in sequence rather than once - first a long EMA (default 25 bars) of the one-bar price change, then a second, shorter EMA (default 13 bars) applied to the first EMA's own output. The same double smoothing is applied to the absolute value of the one-bar change, and TSI is the ratio of the two double-smoothed series, times 100, bounded loosely between -100 and +100 in practice. A short EMA (default 7 bars) of TSI itself is plotted as a signal line. The double-smoothing chain is Blau's own published design, not a simplification of a single-EMA momentum oscillator - it is what makes TSI noticeably smoother than a comparable one-pass momentum ratio while still turning with relatively little lag. Notes and limitations - Needs roughly InpLongPeriod + InpShortPeriod + InpSignalPeriod bars of history before it produces a value. - Each EMA chain is seeded from its own first available value rather than a separate warm-up SMA; this is the common practical convention and converges to the same steady-state values, though the very first few bars of a short history will differ slightly from a vendor implementation that seeds differently. - Recomputed from bar zero on every call, since the double-EMA chain carries state forward from the previous bar with no fixed-length window it can be independently re-derived from mid-history. - This is an oscillator only - it does not generate trade signals or alerts.
Indicator · MT4 · v1.0 · Free
About True Strength Index
True Strength Index is an indicator for MetaTrader 4. It has 3 settings, such as Long period, Short period and Signal period. MQL source code included.
Files in the download: TrueStrengthIndex.mq4, TrueStrengthIndex.txt.
Settings
| Setting | Default | What it does |
|---|---|---|
| Long period | 25 | First (long) EMA period applied to raw momentum |
| Short period | 13 | Second (short) EMA period applied to the first EMA's output |
| Signal period | 7 | EMA period of the TSI signal line |
How to install
- Download the ZIP from your PolyMaria library and unzip it.
- In MetaTrader 4 open File → Open Data Folder, then go to MQL4 → Indicators.
- Copy the .mq4 file(s) there. Put any .mqh files in MQL4 → Include.
- Open the .mq4 file in MetaEditor and press Compile (F7) if MetaTrader does not show it.
- Drag the indicator from the Navigator onto a chart and adjust the settings.
Tags: Moving Average · Momentum · Oscillator · Buy/Sell Arrows · Trend · MT4 Indicator · MQL4 Source Code