34. True Strength Index (TSI)


1. What is True Strength Index (TSI)?

The True Strength Index (TSI) is a momentum-based oscillator developed by William Blau that smooths price changes using double exponential moving averages. It’s designed to identify trend direction, reversals, and momentum strength while filtering out short-term noise.


2. Components of TSI?

  • Momentum = Current Price − Previous Price

  • EMA of Momentum (short-term smoothing, e.g., 25-period)

  • EMA of EMA of Momentum (long-term smoothing, e.g., 13-period)

  • TSI Formula:

    TSI=100×Double EMA of MomentumDouble EMA of Absolute MomentumTSI = 100 \times \frac{\text{Double EMA of Momentum}}{\text{Double EMA of Absolute Momentum}}

Optional: A signal line is usually a 7-period EMA of the TSI.


3. Pros and Cons of True Strength Index?

Pros:

  • Filters out short-term volatility and market noise.

  • Combines trend and momentum in one oscillator.

  • Useful for identifying bullish/bearish divergences and crossovers.

Cons:

  • May lag in fast-moving markets due to smoothing.

  • Less known and supported than RSI or MACD.

  • Can generate false crossovers in flat markets.


4. What is the purpose of TSI in stock analysis?

  • To measure momentum strength and direction.

  • To detect trend changes through crossovers and divergence.

  • To filter trades based on smooth, volume-neutral momentum shifts.


5. How is TSI calculated or derived?

  1. Calculate price momentum = Close − Previous Close.

  2. Apply a short EMA and then a long EMA to the momentum and its absolute value.

  3. Plug into the formula:

    TSI=100×EMA(EMA(Momentum))EMA(EMA(∣Momentum∣))TSI = 100 × \frac{EMA(EMA(Momentum))}{EMA(EMA(|Momentum|))}


6. When should traders use TSI?

  • When looking for momentum reversals with reduced noise.

  • In trend-following strategies for confirmation.

  • To spot bullish/bearish divergence for early warning signals.


7. What are the limitations or risks of using TSI?

  • Can lag in high-volatility or fast-reversal markets.

  • May require custom tuning per asset.

  • Not as effective in range-bound conditions.


8. What are common mistakes when interpreting TSI?

  • Misusing TSI crossovers as standalone buy/sell signals.

  • Ignoring trend or support/resistance context.

  • Not confirming with volume or price structure.


9. How can TSI be combined with other tools for better accuracy?

  • Pair with MACD or RSI to strengthen momentum confirmation.

  • Use with trend indicators like moving averages or ADX.

  • Combine with price action patterns or support/resistance zones.


10. How do professional traders interpret TSI differently from beginners?

Professionals:

  • Focus on divergence and trend-confirmed crossovers.

  • Adjust smoothing periods based on volatility and timeframe.

  • Use TSI slope and histogram-type behavior for momentum insights.

Beginners:

  • Trade every crossover blindly, without filtering.

  • Don’t adjust TSI settings for asset or strategy.

  • Miss subtle signals like fading momentum or divergence.


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