By Islam BarakaDefinitions
In plain terms
It resists an isolated gross outlier by choosing a supported line instead of fitting every point equally.
Technical
The selected method enumerates two-point hypotheses in log-price space, applies inclusive residual tolerance and deterministic tie-breaking, then performs one OLS refit on locked inliers.
Scope
The fitted line is descriptive geometry; projection is not a price forecast.
Formula
select the maximum-consensus two-point log-price line and refit locked inliersh^*=\arg\min_h(-|I(h)|,\operatorname{median}|e_i|,|b_h|,\text{pair order})| Symbol | Meaning | Unit |
|---|---|---|
I(h) | inlier set for hypothesis | set |
Output unit: model
Examples
- A reviewer computes Robust Trendline Fitting on a small deterministic fixture and checks timing, units, and boundary behavior before publication.
Common misconceptions
- The fitted line is descriptive geometry; projection is not a price forecast.
Concept relationships
Related
Required by
- Log-Price Trendline
- Head and Shoulders
- Shoulder Level Comparability
- Head Dominance
- Head-and-Shoulders Pivot Sequence
- H&S Trough Neckline Anchors
- H&S Neckline Projection
- H&S Confirmation Break
- H&S Candidate Availability
- H&S Prior Rise Requirement
- H&S versus Triple Top
- Inverse Head and Shoulders
- Inverse Shoulder Comparability
- Inverse Head Dominance
- Inverse H&S Pivot Sequence
- Inverse H&S Peak Neckline Anchors
- Inverse H&S Neckline Projection
- Inverse H&S Confirmation Break
- Inverse H&S Candidate Availability
- Inverse H&S Prior Decline Requirement
- Inverse H&S versus Triple Bottom
Where this concept is used
Tutorials planned
These catalogued topics use this concept, but their complete build has not shipped yet.
- D08-F01-A04 Primary
Evidence and governance
- Random Sample Consensus: A Paradigm for Model Fitting Fischler and Bolles · first party technical publication
Supports: preferred label, short definition, technical definition, formula
Limits: The original applications are image analysis and cartography, not financial trendlines.
- sklearn.linear_model.RANSACRegressor scikit-learn · first party technical publication
Supports: preferred label, short definition, technical definition, formula
Limits: This package enumerates every two-point hypothesis for small pivot sets instead of using random sampling.
- Linear Least Squares Regression NIST/SEMATECH · official standard
Supports: preferred label, short definition, technical definition, formula
Limits: A fitted line remains descriptive and is not evidence of a future price path.
- numpy.log NumPy · first party technical publication
Supports: preferred label, short definition, technical definition, formula
Limits: A log transform requires positive finite prices and does not by itself define a financial level.
- numpy.polyfit NumPy · first party technical publication
Supports: preferred label, short definition, technical definition, formula
Limits: The glossary freezes its own log-space OLS contract, diagnostics, and tie rules.
- Reviewed by
- fintech-builder-batch-011
- Last reviewed
- 2026-08-09
- Next review
- 2027-08-09
- Record status
- evidence reviewed
This record is evidence-reviewed and readable, but not yet promoted to published — it is served noindex,follow and excluded from the sitemap.