Rounding Bottom Scanner
Most rounding-bottom detectors look for a handful of alternating swing lows that happen to decline then rise, which fires on almost any slow chop as readily as on a genuine saucer. This indicator instead fits a quadratic curve, y = a*x^2 + b*x + c, to every Low price across a sliding window using ordinary least squares (the 3x3 normal equations solved directly by Cramer's rule, no external library needed), and only accepts the window as a rounding bottom when four independent conditions hold together: the curve actually opens upward (a > 0, a true U-shape rather than a downward bend or a straight trend line), its vertex sits roughly in the middle of the window rather than jammed against either edge (which would just mean "price fell" or "price rose", not "price rounded"), the fit's R-squared clears InpMinFitQuality so a handful of coincidentally low bars in an otherwise messy window can't sneak through, and the window's overall depth clears InpMinDepthPercent so a nearly flat, low-volatility stretch isn't mistaken for a saucer just because its curvature happens to be technically positive. Curve fitting catches smooth, gradual bottoms that swing-pivot counting tends to miss entirely, at the cost of being genuinely sensitive to the window length and fit-quality threshold chosen. It says so directly in the notes below rather than implying it is a universal saucer finder. Notes and limitations This is a shape detector, not a breakout predictor: it identifies that a window's price action fits a smooth upward-curving bowl, not that price will subsequently break out upward. Because the window slides one bar at a time, more than one overlapping window can technically qualify around the same true saucer; InpMinBarsBetween exists specifically to cut that down but does not guarantee exactly one signal per real pattern on noisy data. The least-squares fit treats every bar in the window equally regardless of how far in the past it sits, so an otherwise excellent saucer with one deep noise spike can still fail InpMinFitQuality. Intended for H4 and above; lower timeframes will fit plenty of statistically valid but practically meaningless curves.
Indicator · MT5 · v1.0 · Free
About Rounding Bottom Scanner
Rounding Bottom Scanner is an indicator for MetaTrader 5. It draws buy and sell arrows on the chart and can alert you with a pop-up, sound, email or push message. It has 7 settings, such as Window bars, Min fit quality and Min depth percent. MQL source code included.
Files in the download: RoundingBottomScanner.ex5, RoundingBottomScanner.mq5, RoundingBottomScanner.txt.
Settings
| Setting | Default | What it does |
|---|---|---|
| Window bars | 40 | Bars in the fitted window (use higher timeframes for real saucers) |
| Min fit quality | 0.55 | Minimum R-squared for the parabola to be considered a real fit |
| Min depth percent | 0.30 | Minimum window Low-range as a percent of average price |
| Min bars between | 20 | Cooldown bars between two accepted signals |
| Curve segments | 8 | Chord segments used to draw the fitted curve |
| Show curve | true | Draw the fitted parabola across the window |
| Alerts | true | Alert once when a new rounding bottom completes |
How to install
- Download the ZIP from your PolyMaria library and unzip it.
- In MetaTrader 5 open File → Open Data Folder, then go to MQL5 → Indicators.
- Copy the .mq5 file(s) there. Put any .mqh files in MQL5 → Include.
- Open the .mq5 file in MetaEditor and press Compile (F7) if MetaTrader does not show it.
- Drag the indicator from the Navigator onto a chart and adjust the settings.
Tags: Dashboards & Scanners · Buy/Sell Arrows · Alerts · MT5 Indicator · MQL5 Source Code