Free research apps that compute abnormal returns, abnormal volume, and every test statistic you need for publication, from a single event to a portfolio of thousands. Used in peer-reviewed work since 2014.
Supported research by scholars of the following institutions (selection):
Methodology
How event studies work.
The classical MacKinlay (1997) pipeline, with modern extensions for clustering, volatility, and non-parametric inference built in.
Estimation window
t = −250 … −11
Event window
t = −10 … +10
Post-event
t > 10
t = 0
t₀
Define the event
Pick a ticker, a date, and an event window. ARC defaults to [-10, +10] but accepts anything up to [-250, +250].
E(Rᵢₜ)
Fit the expected-return model
Choose market model, CAPM, Fama-French 3 or 5-factor, Carhart 4-factor, or constant mean. Estimation window defaults to [-250, -11].
ARᵢₜ
Compute abnormal returns
ARᵢₜ = Rᵢₜ − E(Rᵢₜ). Daily abnormal returns, aggregated cross-sectionally into AAR and cumulatively into CAR and CAAR.
H₀: AAR=0
Test significance
Apply parametric (t-test, BMP, Patell) and non-parametric (Corrado rank, generalized sign) tests in parallel.
→ .tex
Publish with confidence
Export to LaTeX, CSV, or Stata-ready formats. Every output ships with the model spec and test choice for reproducibility.
An event study is a statistical method that measures how a specific event, such as an earnings announcement, merger, or regulatory decision, moves a company's stock. The steps above trace it: fit a normal-return model over the estimation window, measure the abnormal return (actual minus expected) during the event window around the event date, then cumulate and average those abnormal returns into the CAR and CAAR and test them for statistical significance. New here? Read the methodology guide or look up a term in the glossary.
ARC Capabilities
Everything you need to publish.
Our Abnormal Return Calculator performs the event study for you: all relevant expected-return models and no test statistic left out. Every analysis output ships ready-to-publish.
Expected-return models
Market model
Constant mean
Market-adjusted
CAPM
Fama-French 3-factor
Fama-French 5-factor
Carhart 4-factor
Comparison period mean
Parametric tests
Cross-sectional t
Time-series t
Patell (standardized)
BMP (Boehmer, Musumeci, Poulsen)
Standardized cross-sectional
Adjusted BMP (Kolari-Pynnönen)
Non-parametric tests
Generalized sign
Corrado rank
Corrado-Zivney
Wilcoxon signed-rank
Permutation
Output
AR · AAR · CAR · CAAR · BHAR
p-values at 1 / 5 / 10% levels
CSV · Excel export
Per-firm diagnostics
Email delivery · API
Why our research apps
Built by scholars, for scholars.
A short explainer about what the apps are, who builds them, and how the academic community uses them in publication-grade research.
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