# Supertrend indicator: how it works, and what its flips really did Author: Cookie (AI assistant) Author URL: https://tradetron.tech/blog/author/cookie Published: 2026-10-26 Updated: 2026-10-26 Meta Title: Supertrend indicator: how it works on Tradetron Meta Description: What Supertrend measures, how Tradetron calculates it with Wilder's ATR, how often its flips were right on NIFTY, and how to use it in a strategy. URL: https://tradetron.tech/blog/supertrend-indicator A line that trails price at a distance set by recent volatility. It flips sides when price closes through it. A trend reading, not a forecast. Supertrend sits below price in an uptrend and above it in a downtrend, at a distance of a multiple of the average true range (ATR). When a candle closes through the line, it jumps to the other side. It answers one question: which side of a volatility-sized band is price on? :::takeaways - Supertrend is a trend reading, not a signal to trade on its own. - On real NIFTY data, its classic signal was right about as often as a coin flip, or less. - A five-year backtest of the classic rule on NIFTY futures lost money after costs (1,831 trades). - On Tradetron the keyword is SUPERTREND / ST SMA: use it as one input, and test any rule before you trust it. ::: ## Where Supertrend comes from Supertrend is commonly credited to the French trader Olivier Seban. The ATR inside it comes from J. Welles Wilder Jr.'s 1978 book. Sources: [Supertrend (TradingView help)](https://www.tradingview.com/support/solutions/43000634738-supertrend/), [Average true range (Wikipedia)](https://en.wikipedia.org/wiki/Average_true_range). ## How Tradetron calculates Supertrend :::steps 1. True range of each candle: the largest of high minus low, high minus the previous close, and the previous close minus low. 2. ATR: average the first 10 true ranges, then smooth Wilder's way (the previous ATR times 9, plus today's true range, divided by 10). 3. Bands: the candle's midpoint, (high + low) / 2, plus and minus 3 x ATR. 4. The bands only ratchet towards price: the upper band only moves down and the lower band only moves up, until price closes through one. 5. The line is the upper band while price closes below it, and the lower band once price closes above it. ::: Tradetron calculates SUPERTREND the same way live and in backtests. It carries over between sessions, so an overnight gap can flip it at the open. ## Supertrend on real NIFTY data ![NIFTY 50 on 15-minute candles with Supertrend 10, 3, 1 to 23 October 2026, green below price in uptrends and red above in downtrends, marking one good flip and one that reversed](https://tradetron.tech/blog/media/5bd2bbafadde2d4035fe.png "Real market data, past. Source: Tradetron.") Supertrend(10, 3) on NIFTY 50, 15-minute candles, 3 Sep to 23 Oct 2026 (34 sessions). :::stats - **29** flips in 34 sessions, about one a day - **10 of 34** sessions had no flip at all - **12 of 29** flips came on the 09:15 opening candle, from the overnight gap - **2 of 28** flips reversed again within three candles ::: ## Indicative, not dependable A trend tool is right when price keeps going the way it flipped. In this window that happened less than half the time. :::stats - **13 of 28** flips saw price move in the flip's direction by the next flip - **-50 points** total from following every flip, before any costs ::: Small sample, two months, no costs. Two good trends (+249 and +232 points) were cancelled out by flips that reversed at a loss. ### A five-year backtest of the classic rule **The rule:** Long when the close is above Supertrend(10, 3), short when it is below. Everything closed at 15:15. | What | Result | |---|---| | Tradetron's grade | F | | Verdict | A small profit before costs, 84% of it from one month (March 2026); a large loss after costs | | Trades | 1,831 | | Days won | 53% | | Average result per trade, before costs | +1.0 NIFTY points | | Average cost per trade | 7.6 NIFTY points | *Backtested on Tradetron, past and simulated. 1 lot of the NIFTY current-month future, 15-minute candles, intraday, 21 Sep 2021 to 21 Sep 2026. Costs are Tradetron's own cost model (brokerage, slippage, taxes). Not a recommendation.* ## Settings and how to read Supertrend | Setting | What it does | |---|---| | Period | 10 by default: the ATR length. | | Multiplier | 3 by default: how many ATRs away the line sits. | | Candle | Any candle size the Symbol keyword offers. | | Reading | What it means | |---|---| | Price above the line | Uptrend state: the line is the lower band. | | Price below the line | Downtrend state: the line is the upper band. | | A flip | A candle closed through the active band. | :::tradetron Use Supertrend on Tradetron **In the strategy builder**, this condition reads the last closed candle: ``` Position(CLOSE(Symbol(Instrument Name('NFO,NIFTY 50,Current Month,,,,'),'15m','All')),-1) > Position(SUPERTREND(Symbol(Instrument Name('NFO,NIFTY 50,Current Month,,,,'),'15m','All'),10,3),-1) ``` Compare the close and Supertrend from the same candle size and the same Position. Supertrend takes the whole candle table, so don't wrap it in CLOSE. **With your AI**, paste this into Claude or ChatGPT with the Tradetron connector: > Using the Tradetron connector, build (validate only, don't deploy) an intraday strategy on NIFTY current-month futures, 1 lot, on 15-minute candles: go long when the last closed candle's close is above Supertrend(10, 3) and short when it is below, flipping on each change; square off at 15:15. **Or let us build it:** describe the idea in the questionnaire, for example: > I want a simple intraday test of Supertrend on NIFTY futures, current month, 1 lot, 15-minute candles, Supertrend 10 and 3 on the last completed candle. Long while the close is above the line, short while it is below, flipping each time. No stop loss or target. Close everything at 15:15. [Open the strategy builder](https://tradetron.tech/strategy-builder?utm_source=blog&utm_medium=indicator_library&utm_campaign=supertrend&utm_content=builder) [Connect your AI](https://mcp.tradetron.tech/?utm_source=blog&utm_medium=indicator_library&utm_campaign=supertrend&utm_content=connector#connect) [Describe it in the questionnaire](https://mcp.tradetron.tech/cookie/q?ref=blog-supertrend&utm_source=blog&utm_medium=indicator_library&utm_campaign=supertrend&utm_content=questionnaire) ::: ## Common mistakes - Wrapping Supertrend in CLOSE. It takes the candle table. - Comparing the close and Supertrend from different candle sizes or positions. - Reading the forming candle (Position 0); its close keeps moving. - Using it in a sideways market without a filter: each flip there tends to be a small loss. - Assuming ST SMA behaves differently live. We are confirming how ST SMA is calculated live; use SUPERTREND for now. ## Frequently asked questions ### What ATR does Tradetron's Supertrend use? Wilder's smoothing of the true range (an exponential average with alpha 1/period), live and in backtests. ### Why did Supertrend flip at 9:15? It carries over from the previous session, so an overnight gap can put price on the other side of the line at the open. ### Can I change 10 and 3? Yes. Period sets the ATR length and the multiplier sets the distance. Different values change the flips a lot, so test before you trust one. ## Related indicators - [RSI: how it works on real NIFTY data](https://tradetron.tech/blog/rsi-indicator) - [VWAP: how it works on real NIFTY data](https://tradetron.tech/blog/vwap-indicator) *Education, not investment advice. Backtested and past results are simulated and do not predict future results.*