diff --git a/CHANGELOG.md b/CHANGELOG.md
index f73d63bf..e75d2638 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,7 +5,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
+## [3.5.3] - 2026-06-25
 
 ### Added
 - **`generate_synthetic_control_data()` data generator + a capstone `SyntheticControl` tutorial.** New public generator (`diff_diff/prep_dgp.py`, exported from `diff_diff`) builds a **single-treated-unit** factor-model panel for synthetic-control demos and tests: one treated unit whose latent factor loadings and baseline are an exact convex combination of a few donors (so the noiseless trajectory lies in the donor convex hull and a synthetic control reproduces it closely — the observed fit is approximate under added noise), persistent AR(1) factors, predictor covariates that each proxy a distinct factor, a common calendar time effect, and a known `"ramp"` or `"constant"` treatment effect emitted as `true_effect`. Tutorial **`docs/tutorials/25_synthetic_control_policy.ipynb`** walks the whole `SyntheticControl` surface end-to-end on a policy-evaluation story (one state adopts a clean-energy standard), structured around **two inference philosophies**: cross-unit permutation (`in_space_placebo` + Firpo–Possebom `confidence_set`, with `leave_one_out` / `in_time_placebo` robustness) versus over-time conformal (CWZ `conformal_test` / `conformal_confidence_intervals` / `conformal_average_effect`), with the per-period conformal band as the climax. A `tests/test_t25_synthetic_control_policy_drift.py` drift guard re-derives every quoted number from the generator.
@@ -1609,6 +1609,7 @@ for the full feature history leading to this release.
 [2.1.2]: https://github.com/igerber/diff-diff/compare/v2.1.1...v2.1.2
 [2.1.1]: https://github.com/igerber/diff-diff/compare/v2.1.0...v2.1.1
 [2.1.0]: https://github.com/igerber/diff-diff/compare/v2.0.3...v2.1.0
+[3.5.3]: https://github.com/igerber/diff-diff/compare/v3.5.2...v3.5.3
 [3.5.2]: https://github.com/igerber/diff-diff/compare/v3.5.1...v3.5.2
 [3.5.1]: https://github.com/igerber/diff-diff/compare/v3.5.0...v3.5.1
 [3.5.0]: https://github.com/igerber/diff-diff/compare/v3.4.2...v3.5.0
diff --git a/CITATION.cff b/CITATION.cff
index 1ae9472c..f64a0289 100644
--- a/CITATION.cff
+++ b/CITATION.cff
@@ -7,8 +7,8 @@ authors:
     family-names: Gerber
     orcid: "https://orcid.org/0009-0009-3275-5591"
 license: MIT
-version: "3.5.2"
-date-released: "2026-06-08"
+version: "3.5.3"
+date-released: "2026-06-25"
 doi: "10.5281/zenodo.19646175"
 url: "https://github.com/igerber/diff-diff"
 repository-code: "https://github.com/igerber/diff-diff"
diff --git a/diff_diff/__init__.py b/diff_diff/__init__.py
index 75a52a07..886889df 100644
--- a/diff_diff/__init__.py
+++ b/diff_diff/__init__.py
@@ -299,7 +299,7 @@
 DCDH = ChaisemartinDHaultfoeuille
 HAD = HeterogeneousAdoptionDiD
 
-__version__ = "3.5.2"
+__version__ = "3.5.3"
 __all__ = [
     # Estimators
     "DifferenceInDifferences",
diff --git a/diff_diff/guides/llms-full.txt b/diff_diff/guides/llms-full.txt
index 6d6dccca..5b3f1a6d 100644
--- a/diff_diff/guides/llms-full.txt
+++ b/diff_diff/guides/llms-full.txt
@@ -2,7 +2,7 @@
 
 > A Python library for Difference-in-Differences causal inference analysis. Provides sklearn-like estimators with statsmodels-style output for econometric analysis.
 
-- Version: 3.5.2
+- Version: 3.5.3
 - Repository: https://github.com/igerber/diff-diff
 - License: MIT
 - Dependencies: numpy, pandas, scipy (no statsmodels dependency)
diff --git a/pyproject.toml b/pyproject.toml
index 10166ba3..52e1308f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "maturin"
 
 [project]
 name = "diff-diff"
-version = "3.5.2"
+version = "3.5.3"
 description = "Difference-in-Differences causal inference with sklearn-like API. Callaway-Sant'Anna, Synthetic DiD, Honest DiD, event studies, parallel trends."
 readme = "README.md"
 license = "MIT"
diff --git a/rust/Cargo.toml b/rust/Cargo.toml
index 1ec6e287..e08d5e94 100644
--- a/rust/Cargo.toml
+++ b/rust/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "diff_diff_rust"
-version = "3.5.2"
+version = "3.5.3"
 edition = "2021"
 rust-version = "1.85"
 description = "Rust backend for diff-diff DiD library"