True range
True range is a single bar's real travel: the largest of the day's high-to-low span and the distances from either extreme back to the previous close, so overnight gaps count as movement.
`true_range` measures how far a stock actually travelled in one session, gaps included. It is the largest of three spans: today's high minus today's low, the distance from today's high back to yesterday's close, and the distance from today's low back to yesterday's close. The plain high-low range misses the overnight move. A stock that gaps down 4% and then trades a tight day did not have a quiet session, and true range says so.
On its own the number is in rupees, so it means little across stocks. The useful form compares it to the stock's own average. Below `0.5x atr(14)` is a narrow-range day, the coil the Narrow range day scan looks for, on the observation that abnormally quiet sessions tend to sit just before abnormally loud ones. Above `2x atr(14)` is a range expansion, the loud day itself, with the close's direction saying which side won it.
Being a single-bar measure is both its point and its limit. One session's true range is one observation, dominated by whatever happened that day, and it carries no direction: a huge true range can be a surge, a collapse, or a violent round trip that closed flat. Pair it with `change` or the close's position when direction matters, and with a turnover floor in thin names, where a wide range can mean a handful of trades.
Its sibling ATR is simply Wilder's 14-bar average of this field. True range is today's travel; ATR is what travel has been typical lately. Nearly every use of one involves the other, and the ratio of today's true range to ATR is how a ₹50 stock and a ₹5,000 stock get compared on the same scale.
In Sift
Written as true_range — a price amount, per bar; usually compared against atr(14). A working scan — A session twice the stock's normal size, resolved in the buyers' favour:
where true_range > 2x atr(14) and change > 01
of the 500 most-traded NSE stocks match today, as of 25 Sept 2026
Scans that use it
Prebuilt scans in the library whose query reads this value — each with a hit-rate replay over the last 250 sessions.
Common questions
What is the difference between true range and ATR?
True range is one bar's measurement, the day's real travel including any gap from the previous close. ATR is Wilder's 14-bar smoothed average of that measurement, a stock's normal daily travel. Scans typically compare the two: true range below half of ATR is a compression day, above twice ATR an expansion day.
Why not use high minus low?
Because the plain range ignores gaps. A stock that closes at 100, opens at 96 and trades between 95 and 97 shows a high-low range of 2, but it moved 5 from yesterday's close. True range takes the previous close into account, so overnight moves count as the volatility they are.
What does a high true range day mean?
That the session travelled far more than usual: stops run, a level surrendered, news absorbed. Direction is not in the reading, and the same number fits a surge, a collapse or a round trip. The close relative to the open, or the day's change, tells you which side absorbed the move.