True Strength Index (TSI) Indicator Guide

TSI starts with a simple idea: measure how much price changed from one bar to the next, then smooth that change twice to remove noise. The first smoothing uses a 25-period EMA of the raw price change. The second applies a 13-period EMA on top of that result — this double-smoothing is what separates TSI from single-smoothed momentum oscillators like ROC or raw momentum. The final value is expressed as a ratio: the double-smoothed price change divided by the double-smoothed absolute price change, multiplied by 100. That division step normalizes the output to the -100 to 100 range regardless of the asset's price level, making TSI directly comparable across instruments — a EUR/USD reading of +35 carries the same meaning as a gold reading of +35. A 7-period EMA of the TSI line itself serves as the signal line, mirroring the structure of MACD. The math, while layered, produces one practical outcome: trend direction is reflected quickly, and momentum reversals appear with less delay than a standard 14-period RSI would generate on the same data.

Four distinct signal types emerge from TSI. First, zero-line crossovers: when TSI crosses above zero, momentum has shifted bullish; a cross below zero signals bearish momentum. These are the broadest signals and work best on D1 charts where false crosses are filtered by the longer timeframe context. Second, signal-line crossovers: when the TSI line crosses above its 7-period signal line, that constitutes a buy trigger; crossing below generates a sell trigger. These are faster and more frequent than zero-line crosses. Third, overbought and oversold readings: values above +25 suggest overbought conditions while readings below -25 indicate oversold territory — though in strong trending markets, TSI can hold above +25 for extended periods without reversing. Fourth, and arguably most reliable, is divergence. Bullish divergence occurs when price prints a lower low while TSI prints a higher low — a sign that selling momentum is fading. A practical example: during the EUR/USD decline between August and October 2022, TSI on the D1 chart formed a bullish divergence pattern near the 0.9600 price zone approximately two weeks before the pair staged a 600-pip recovery. Bearish divergence — price making a higher high while TSI makes a lower high — carries equivalent weight on the sell side.

The default parameters of 25/13/7 were designed with daily charts in mind. On D1, those defaults perform well for swing trading, capturing multi-day momentum shifts without excessive noise. The 25-period long EMA spans approximately five trading weeks, giving the indicator enough historical context to filter intraday volatility. On H4 charts, shortening the long period to 20 and the short period to 10 (keeping signal at 7) produces more responsive readings suitable for 2-to-5 day position trades. Signals remain meaningful without the indicator becoming erratic. H1 presents the greatest challenge. At default settings, TSI on H1 lags enough to miss fast intraday moves. Reducing parameters to 13/7/5 brings responsiveness closer to what traders expect on a one-hour chart, though the trade-off is a higher rate of false signal-line crossovers during ranging sessions. A practical rule: on any timeframe below H4, confirm TSI signal-line crossovers with a secondary condition — such as the zero line being on the same side as the crossover direction — before acting. This single filter can materially reduce false entries during low-volatility periods.

TSI functions most effectively as a confirmation tool rather than a standalone entry trigger. A common framework pairs TSI with a trend-following indicator like a 50-period EMA: only take TSI buy signals when price is above the 50 EMA, and only take sell signals when price is below it. This directional filter eliminates a significant portion of counter-trend whipsaws. For exits, TSI divergence against an open position provides an objective, rules-based reason to close — more systematic than relying on fixed profit targets alone. Stop-loss placement can be anchored to the swing high or low that preceded the TSI crossover signal, giving each trade a logical invalidation point. Pulsar Terminal's multi-level SL/TP and one-click order tools allow traders to set these TSI-derived stop and target levels directly on the MetaTrader 5 chart the moment a signal appears, reducing execution delay between signal identification and order placement. One underappreciated application of TSI is monitoring it during news releases: a TSI reading already at extreme levels (+30 or -30) before a high-impact event suggests momentum is stretched, and any surprise in the opposite direction could accelerate a reversal rather than extend the existing move.