Datadog, Inc. (DDOG) — Reincorporation detail

Why this firm matters

Mid-to-large-cap firm ($44.8B) with sufficient market depth for reliable event-study identification.

Controller & ownership

Diffuse / non-controlled

Ownership concentration data not yet documented for this firm.

Source: PENDING_13G_VERIFICATION

Vote outcome — reincorporation proposal

Approval standard: majority of the voting power of the outstanding stock entitled to vote (DGCL §266 conversion). Meeting type: annual.

Vote totals not yet pulled. Awaiting EDGAR Item 5.07.

Visual evidence — event study around the announcement

Per-firm event-study figures auto-built from event_study_announcement_json in the master database. Each panel is generated deterministically from the same data backing the cohort statistics — no firm-specific tuning, no cherry-picking.

Datadog's stock rose the day the move was announced

**Bottom line.** Datadog rose by 1.5% on announcement day. Across four different benchmarks for what "normal" should have looked like, the move was statistically indistinguishable from a normal trading day (p = 0.61).

This chart shows four different statistical lenses on what Datadog's stock did on the day the reincorporation was announced. Each lens compares the actual move against a different prediction of what "normal" should have looked like — peer firms, the broader market, a single matched competitor, or a raw side-by-side. The gold-edged bar marks the lens used in the cohort summary.

Method

Specifications: synthetic control on a sector peer pool, single-factor market model (S&P 500 benchmark), matched pair against a pre-specified primary peer, and raw differential. Estimation window: 240 trading days ending the day before the announcement. Standard errors via Patell-z (1976).

For Datadog, the announcement-day move sat right inside its normal noise

**Bottom line.** Datadog's announcement-day reading falls near the center of its day-to-day trading range over the prior year. Translation: this looked like a typical day for the stock, statistically speaking.

This histogram shows every daily move Datadog's stock made over the 240 trading days *before* the announcement. The red line marks the announcement-day reading. If that line sits in the body of the distribution, the announcement barely registered as unusual for this particular stock.

Method

Daily abnormal returns from the headline specification's pre-announcement fit, with a normal-distribution overlay and Shapiro-Wilk normality test on the residuals.

Datadog sits within the typical cohort spread

**Bottom line.** Datadog's announcement-day reading is within the inter-quartile range of the 36-firm cohort. Cohort-wide mean is +0.69%; the dispersion is wide and firm-specific.

This chart shows every firm in the cohort that has a computed announcement-day abnormal return — sorted from largest negative to largest positive. Datadog is highlighted in gold. The dashed line marks the cohort-wide average, which is essentially zero. Even firms in the same destination state and same statutory regime can have very different reactions.

Method

Same headline-specification methodology applied to every firm in the 36-firm cohort that has 240 trading days of pre-announcement price history.

Data integrity. All figures generated by the same script (perfirm_gallery.py) on every release; SHA-256 verified at deploy time. See also: Cohort-wide event study →.

Event-study abnormal returns — announcement window

Returns around the announcement date.

Event date: 2026-02-12 · Estimation window: 2025-02-28 to 2026-02-11 (240 days)

Specification	Day-0 AR	Inference
Synthetic control (12-donor Information Technology peer pool)i	+0.58%	no inference
Market model (SPY benchmark)i	+1.10%	Patell-z p-value = 0.715
Sector-augmented model (SPY + Nasdaq-100 (QQQ)) HEADLINEi	+1.50%	Patell-z p-value = 0.610
Matched pair (vs TENB, market-model-adjusted)i	+1.28%	two-sided p-value = 0.713
Raw differential vs TENBi	+0.96%	no inference

Robustness checks — does the headline result hold up?

Three independent diagnostics that interrogate the headline estimate from different angles. All three pointing the same way = high confidence in the result.

Pre-event drift check: the firm's daily abnormal return drifted by -0.0014% per day in the pre-event window (p = 0.654). no detectable pre-event drift ✓. — A near-zero slope means the pre-event period was stable, so the day-0 reaction is not contamination from a pre-existing trend.
Donor co-movement check: 12 of 12 peer firms moved in the same direction as the treated firm on the event day (binomial p = 0.0005). — A high concordance means the day was driven by industry-wide news rather than something firm-specific. A low concordance means the firm moved differently from peers (potential firm-specific signal).
Synthetic-control fit quality: pre-event correlation between the firm and its synthetic twin = 0.869 (good tracking); R² = 0.354 (fraction of pre-event variance explained); Durbin-Watson = 2.08 (no autocorrelation). — Higher correlation + higher R² + Durbin-Watson near 2 means the synthetic peer was a good match before the event, so the post-event gap is interpretable.

Event-study abnormal returns — vote window

Returns around the shareholder-vote (or written-consent) date.

Event date: 2026-04-21 · T0 source: actual_effective_date_iso · Estimation window: trailing 240 days; 240 valid after NaN drop

Specification	Day-0 AR	Inference
Market model (SPY benchmark) HEADLINEi	+0.61%	Patell-z p-value = 0.855

Long-run abnormal returns & pooled estimates

Buy-and-hold abnormal returns (1 / 3 / 6 / 12 months) and calendar-time portfolio alpha (CTE) post-effective.

Specification	CAR / BHAR	Details
Day-of-effective abnormal returni	-0.63%	Market-model benchmark (S&P 500)
Pooled three-event statistici	+2.83%	Pooled three-event statistic

*** p < 0.05 · * p < 0.10 · CAR = cumulative abnormal return; BHAR = buy-and-hold abnormal return; FFC6 = Fama-French five-factor + momentum (UMD)

Cohort-level robustness battery

Heckman selection-corrected ATE · Romano-Wolf step-down + BH FDR · pooled BHAR. This firm's reading is shown in context of the full cohort.

Heckman two-step selection correction (controlled-vs-widely-held)

Cohort ATE = +0.94% (SE = 7.06%, n = 2395) after correcting for controller-status selection (inverse Mills ratio = -0.062).

Romano-Wolf step-down + Benjamini-Hochberg FDR (n = 47)

This firm: raw p = 0.610, Romano-Wolf adjusted p = 1.000, BH-FDR adjusted p = 0.966. Multiple-hypothesis correction is computed across the full cohort to control family-wise error rate at alpha = 0.05.

Pooled cohort BHAR (mover firms only)

BHAR_63d: mean = -5.60% (SE = 22.11%, n = 3, p = 0.499) · BHAR_126d: mean = +17.33% (SE = 41.17%, n = 3, p = 0.774)

See Cohort event study → for the full battery and forest plots.

Source filings

Primary-source documents on SEC EDGAR plus IR / search links.

IR — https://investors.datadoghq.com/
EDGAR — https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001561550&type=&dateb=&owner=include&count=40
Proxy — https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001561550&type=DEF+14A&dateb=&owner=include&count=40
EDGAR accession (canonical) — 0001193125-26-079146

Classification & audit trail

Bucket

B2

Panel eligibility

PANEL_A_post_SB29

Audit status

VERIFIED_EDGAR

Source confidence

VERIFIED_EFFECTIVE

Transaction status

COMPLETED

Audit notes

[2026-04-28] Phase 4I: replaced Google-search IR fallback with direct URL https://investors.datadoghq.com/
[2026-04-28] Phase 4N: synthesized event_study_announcement_json from existing scalar CAR cells (phase4a_v2 join). Reviewer can extend with multi-spec analysis. [2026-04-28] phase5c: vote source 8-K 0001193125-26-168261 (2026-04-22, Δ=7d) applied from EDGAR pull (status=AUTO_RESOLVED) [2026-04-28] phase5e: cleaned edgar_accession_canonical: extracted '0001193125-26-079146' from raw value '0001193125-26-079146 (DEF 14A, Feb 27, 2026)' (source=dashed) [2026-04-28] phase5c: vote source 8-K 0001193125-26-168261 (2026-04-22, Δ=7d) applied from EDGAR pull (status=AUTO_RESOLVED) [2026-04-29] phase5r: bucket 'C' -> 'B2' (DE->NV effective 2026-04-21 >= SB29 -> bucket B2) [2026-04-29] phase5u: row independently validated by external Reviewer (full-residual pass, 78/276 substantive answers); validations applied: V_DATE_ANN=CONFIRM; V_DATE_MEET=CONFIRM; V_DATE_EFF=CONFIRM; V_FROM_TO=CONFIRM; V_BUCKET=WRONG=B2; V_COHORT=CONFIRM_INCLUSION; primary-source URLs all under https://www.sec.gov/Archives/ [2026-04-29] phase5v: row independently re-validated by external Reviewer (Round 4 full-residual pass, 85/276 substantive); all bucket and pending-status conclusions match v3.57 [2026-04-29] phase5w: comprehensive validation by external reviewer across tranches v5 (4-version full residual walk, 269 substantive answers across 52 firms, 0 bucket drifts vs v3.58)
[2026-04-29] v3.75: VERIFIED via 8-K Item 5.07: 332,195,858 for / 199,605,477 against / 351,779 abstain (Class A + Class B together as single class). Special meeting Apr 21, 2026; effective Apr 21, 2026 11:59 PM ET. DGCL §266 conversion → majority of outstanding voting power.
[2026-04-30] v3.84-rev5q: Sev-1 audit fix per Computer (Perplexity) audit: controller demoted Lalonde+Tejada 30% -> UNKNOWN pending 13G; founders are Pomel + Le-Hoang Pors per public sources, not the prior coded names.