Trend Intensity Index (TII): Formula, Worked Example and Indian Settings

What the Trend Intensity Index Actually Measures

The Trend Intensity Index (TII) answers one focused question: over the recent past, has price spent more time above its moving average or below it, and by how much. It was popularised by M.H. Pee in Technical Analysis of Stocks and Commodities to grade the conviction behind a move. Where RSI measures momentum of price changes, TII measures positioning relative to a trend line, making it a cleaner trend strength gauge for index traders watching Nifty 50 or Bank Nifty.

The output is bounded between 0 and 100. A value near 100 means almost every recent close sat above the moving average and the gaps were wide, a textbook strong uptrend. A value near 0 means the opposite, and 50 is the neutral line where positive and negative deviations cancel out. Because it is bounded and smooth, TII reads cleanly on a separate pane below your Nifty chart and codes easily into an automated rule.

The important correction for Indian traders: TII is not simply the ratio of up days to total days, and it is not the same as RSI. It weights the size of each close's distance from the average, so a few large breakaway days push it up faster than many tiny green candles. That magnitude sensitivity is why it shines in fast, news driven sessions around RBI policy or the Union Budget.

The Correct TII Formula, Step by Step

Here is the formula stated correctly. Choose a moving average period P, commonly 30, and compute the simple moving average (SMA) of closing price over P days. Then choose a deviation look back window n, commonly half of P, so 15. For each of the last n days, take the deviation, which is that day's close minus that day's SMA value.

• Deviation on day i = Close(i) minus SMA(i). It is positive when price closed above the average, negative when below.
• SDpos = the sum of only the positive deviations across the last n days.
• SDneg = the sum of the absolute values of only the negative deviations across the last n days.
• TII = SDpos divided by (SDpos plus SDneg), then multiplied by 100.

In plain English, TII is the share of total deviation that came from days price closed above its trend line. If every day in the window closed above the average, SDneg is zero and TII reads 100. If every day closed below, TII reads 0. Balanced up and down gaps land you near 50. This is the standard definition used by most charting platforms. The older description that compared up closes to absolute closes is a misstatement and gives different, less reliable numbers.

A Fully Worked TII Calculation on Reliance Industries

Numbers below are illustrative for teaching the method, not a live quote. Assume Reliance Industries has been trending up, and we use a short window suited to swing trading: SMA period P equal to 10, deviation window n equal to 5. Suppose the 10 day SMA on each of the last five sessions and the actual closes were as follows.

Now split the deviations. The positive deviations are +40, +45, +12 and +47, so SDpos = 40 plus 45 plus 12 plus 47 = 144. The only negative deviation is -16, so its absolute value gives SDneg = 16. Apply the formula: TII = 144 divided by (144 plus 16), times 100. That is 144 divided by 160, which is 0.90, times 100, giving TII = 90.

A reading of 90 tells you Reliance is in a strong, well established uptrend: price spent the window comfortably above its moving average and the one down day was small. This is a trend you ride, not one you fade. Notice how a single large up day, Day 4 at +47, contributes more than three small green days would, the magnitude weighting that makes TII different from a simple up day count.

Reading the Score: Zones and What to Do

Treat TII as a strength meter, not a buy and sell button. The most useful structure is three zones. Above 80 means a powerful trend that is worth trading with, between 20 and 80 is a grey area that depends on context, and below 20 means a powerful downtrend. The 40 to 60 belt is the danger zone, because price is flip flopping around its average and any crossover signal there is likely noise.

The 50 line crossover can act as a coarse trigger, but on its own it whipsaws badly in range bound Nifty sessions. A more disciplined approach is to wait for TII to cross above 80 and hold before adding to longs, and to flatten or hedge when it slips back under 50 from a high reading, which often marks the first crack in a trend.

Best TII Settings for Nifty, Bank Nifty and Stocks

There is no single perfect setting, but the period controls the trade off between speed and noise. A short window reacts fast and suits intraday Bank Nifty, where moves are violent. A long window is slower and steadier, better for positional trades in large caps like HDFC Bank or TCS where you want to filter out daily chop.

• Intraday Nifty and Bank Nifty: SMA period 20 with a 10 day deviation window, or even tighter on 5 and 15 minute charts, to catch fast directional days.
• Swing trading stocks (3 to 15 days): SMA period 30 with a 15 day window, the classic default, a good balance of responsiveness and reliability.
• Positional and investing: SMA period 60 with a 30 day window, which smooths out short term volatility and only flags durable trends.
• High beta or news heavy names: lengthen the period so a single gap day does not yank the reading around.

Always backtest a setting on the specific instrument first. Bank Nifty is concentrated in a handful of heavyweight lenders, so the same period can behave quite differently from Nifty 50. Settings that look great in a trending year can fall apart in a sideways one, so test across at least one full cycle.

Trading TII With a Real Bank Nifty Options Example

Numbers here are illustrative and not a recommendation. Suppose it is a Wednesday, Bank Nifty spot is at 48,200, and your TII on the 15 minute chart has just crossed above 82 and is rising, confirming a strong intraday uptrend. You decide to express a bullish view by buying one lot of the weekly 48,300 call. Bank Nifty's lot size is 30, and the call is trading at a premium of 180 rupees.

• Entry cost (debit): 180 premium times 15 = 2,700 rupees, plus charges. This is your maximum loss if the call expires worthless.
• TII confirms the move: over the next two hours Bank Nifty rallies to 48,650 and the call premium rises to 320 rupees.
• Exit value: 320 times 15 = 4,800 rupees.
• Gross profit before charges: 4,800 minus 2,700 = 2,100 rupees on one lot.

Now account for costs, which retail traders routinely ignore. On options, STT is 0.1 percent of the premium on the sell side (effective 1 October 2024), so on the 4,800 rupee sell value that is about 5 rupees. A discount broker charges roughly 20 rupees flat per order, so 40 rupees round trip. Add exchange transaction charges, SEBI fees, stamp duty and 18 percent GST on brokerage and exchange charges, another 15 to 25 rupees. Total charges land near 65 to 70 rupees, leaving a net profit close to 2,030 rupees on this single illustrative lot.

Combining TII With Other Tools

TII is most powerful when it agrees with an independent signal. The cleanest pairings are with a price structure read and a momentum oscillator, because each covers a blind spot of the other. Structure tells you where, momentum tells you how hard, and TII tells you how committed the trend is.

• TII plus a moving average: only take longs when price is above the 50 day average and TII is above 60. This stacks trend direction on top of trend strength.
• TII plus RSI: if TII is above 80 but RSI is above 75 and stalling, the trend is strong but stretched, so wait for a pullback rather than chasing.
• TII plus volume: a TII surge backed by rising volume is far more trustworthy than one on thin volume, which often fades.
• TII plus support and resistance: a strong TII reading that stalls right under a known Nifty resistance is a warning, not a green light.

Avoid stacking three tools that measure the same thing, such as TII, RSI and stochastics together, because they simply nod along and give false confidence. A divergence, where TII stays high but price stops making new highs, is one of the more reliable early warnings that a trend is tiring.

Limitations, False Signals and Risk Control

Every trend tool fails in a range, and TII is no exception. In a sideways Nifty market the reading bounces around 50 and the 50 line crossover generates a stream of losing whipsaws, the single biggest source of damage. So the first rule is simple: do not trade TII crossovers when the reading is stuck between 40 and 60. Wait for it to commit to a zone.

TII is also a lagging confirmation, not a forecast. By the time it reads 90, much of the move may already be behind you, so chasing a high reading late in a trend exposes you to the reversal. Treat extreme readings as a reason to manage an existing position, not to open a fresh full sized one. On Nifty weekly expiry days, intraday TII can spike on a single sharp move that reverses within minutes, so size down or stand aside.

• Always use a stop. Decide before entry where you are wrong, in points and in rupees, and honour it.
• Size by risk, not by capital. Risk a fixed small percentage of your account per trade so one bad signal cannot do lasting harm. Use a position size calculator.
• Respect the calendar. RBI policy, Budget day and major results can flip a strong trend in one candle.
• Journal every TII trade. Record the reading at entry and the outcome so you learn which settings actually work on your instruments.

Taxes and Costs on TII Based Trades in India

How your TII profits are taxed depends on what you trade. Futures and options gains are treated as business income, added to your other income and taxed at your slab rate, with no special capital gains rate. There is no STCG or LTCG concept for F&O. Above the prescribed turnover thresholds you may also fall under tax audit rules, so keep clean records, which is exactly where a trade journal helps.

If you instead use TII to swing trade delivery equity, capital gains rules apply. Shares sold within 12 months attract short term capital gains tax of 20 percent, and shares held longer than 12 months attract long term capital gains tax of 12.5 percent on gains above 1.25 lakh rupees per year (rates effective from the 23 July 2024 changes). Equity delivery also carries STT of 0.1 percent on both buy and sell. These are costs and taxes that quietly shrink your edge, so build them into your expectations before you act on a TII signal.

Putting It All Together

The Trend Intensity Index grades how strongly price is leaning relative to its own moving average, nothing more. Used with the proper deviation based formula rather than the loose ratio many sites quote, it keeps you on the right side of strong Nifty and Bank Nifty trends and warns you off the chop in between, and the worked Reliance example shows the maths is simple once you compute deviations against the matching daily SMA.

Make it a confirmation layer, not a standalone system. Combine it with structure, volume and a fixed stop, respect the sideways zone where it fails, and account for STT, brokerage and the business income tax treatment on F&O before you count any profit.

Sources and Further Reading

For authoritative data and further reading, refer to Zerodha Varsity, Investopedia, NSE India and the Income Tax Department. Always confirm current rules, rates and contract specifications on the official source before you trade.

Sources and Further Reading

For authoritative data and further reading on this topic, refer to Zerodha Varsity, Investopedia, NSE India and Reserve Bank of India. Always confirm current rules, rates and contract specifications on the official source before you trade.