Coinbase Global, Inc. (COIN) — Reincorporation detail

Why this firm matters

Mid-to-large-cap firm ($54.5B) with sufficient market depth for reliable event-study identification.

Controller & ownership

DE FACTO CONTROLLER

Brian Armstrong holds approximately 50.0% of voting power. Founder-dominant via dual-class supervoting structure but does not exceed the strict 50% listing-rule threshold; treated as effective controller for governance purposes.

Source: Dual-class B (10:1)

Vote outcome — reincorporation proposal

Approval standard: majority of voting power of outstanding shares of capital stock entitled to vote (written consent under DGCL §228). 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.

Coinbase Global's stock fell the day the move was announced

**Bottom line.** Coinbase Global fell by 2.1% 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 = 0.62).

This chart shows four different statistical lenses on what Coinbase Global'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 Coinbase Global, the announcement-day move sat right inside its normal noise

**Bottom line.** Coinbase Global'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 Coinbase Global'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.

Coinbase Global sits within the typical cohort spread

**Bottom line.** Coinbase Global'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. Coinbase Global 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: 2025-10-28 · Estimation window: 2024-11-11 to 2025-10-27 (240 days)

Specification	Day-0 AR	Inference
Synthetic control (11-donor Financials peer pool)i	+0.59%	no inference
Market model (SPY benchmark)i	-2.36%	Patell-z p-value = 0.574
Sector-augmented model (SPY + Bank sector ETF (KBE)) HEADLINEi	-2.10%	Patell-z p-value = 0.615
Matched pair (vs HOOD, market-model-adjusted)i	-1.37%	two-sided p-value = 0.802
Raw differential vs HOODi	-1.99%	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 +0.0022% per day in the pre-event window (p = 0.631). 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: 9 of 11 peer firms moved in the same direction as the treated firm on the event day (binomial p = 0.0654). — 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 = 0.776 (modest tracking); R² = -4.105 (fraction of pre-event variance explained); Durbin-Watson = 1.76 (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: 2025-12-15 · 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	-6.01%	Patell-z p-value = 0.111

Long-run abnormal returns & pooled estimates

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

Effective date: 2025-12-15 · n_post = 93 days

Buy-and-hold abnormal returns (BHAR)

Horizon & benchmark	BHAR	Inference
1 month vs S&P 500	-6.44%	Patell-z = -0.28 · p = 0.780 · n = 21 days
1 month vs sector ETF (XLF)	-3.67%	Patell-z = -0.28 · p = 0.780 · n = 21 days
3 months vs S&P 500	-16.67%	Patell-z = -0.14 · p = 0.891 · n = 63 days
3 months vs sector ETF (XLF)	-8.58%	Patell-z = -0.14 · p = 0.891 · n = 63 days

Calendar-time portfolio alpha (CTE)

Specification	Annualized alpha	Inference
Calendar-time portfolio alpha vs S&P 500	-73.10%/yr	t = -1.19 · p = 0.235 · n = 93 days · Newey-West HAC SE (lag=5)
Calendar-time portfolio alpha vs sector ETF	-40.19%/yr	t = -0.43 · p = 0.670 · n = 93 days · Newey-West HAC SE (lag=5)

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 = 0.615, 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.

Texas Statutory Adoptions

Texas opt-in statutory regimes available to Texas-incorporated public companies. Each requires a charter or bylaw amendment with proxy notice. Both are independently elected.

SB 29 — TBOC §21.552

Derivative-action 3% ownership threshold (effective 2025-05-14, post-Tornetta v. Musk).

○ NOT ADOPTED

SB 1057 — TBOC §21.373

Shareholder-proposal threshold: lesser of $1M market value or 3% of voting shares, 6-month hold, 67% solicit (effective 2025-09-01). Director nominations and procedural resolutions are exempt. Legal status: vulnerable to challenge under the Internal Affairs Doctrine and dormant Commerce Clause; SEC Rule 14a-8(i)(1) permits state-law exclusion, so §21.373 may operate through Rule 14a-8 rather than face direct preemption. No court ruling has issued. Firms appear to be in a wait-and-see posture pending legal clarity.

PENDING VERIFICATION

Adoption is opt-in. A "No" or "Pending" status means the firm has not (yet) elected into the regime — it does not mean the firm is non-compliant. Adoption requires a charter/bylaw amendment disclosed via 8-K Item 5.03.

Source filings

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

IR — https://investor.coinbase.com/
EDGAR — https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001679788&type=&dateb=&owner=include&count=40
Proxy — https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001679788&type=DEF+14A&dateb=&owner=include&count=40
EDGAR accession (canonical) — 0001679788-25-000247

Classification & audit trail

Bucket

B1

Panel eligibility

PANEL_A_post_SB29

Audit status

VERIFIED_EDGAR

Source confidence

VERIFIED_EFFECTIVE

Transaction status

COMPLETED

Audit notes

VERIFY: Coinbase effective 2025-12-15 (post-SB 29); must be excluded from Panel B.
Effective date present but no Accession URL in v6 rev78; retrieve from EDGAR.
[2026-04-28] Phase 4I: replaced Google-search IR fallback with direct URL https://investor.coinbase.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. [2026-04-29] phase5g: vote_source set DEF 14C acc=0001679788-25-000218 url=https://www.sec.gov/Archives/edgar/data/1679788/000167978825000218/coin-pre14cinformationstat.htm (written-consent transaction; reviewer: https://www.sec.gov/Archives/edgar/data/1679788/000167978825000218/coin-pre14cinformationstat.htm PRE 14C information statement filed 2025-12 confirming COIN reincorporation approved by majority shareholder written consent (no shareholder meeting). 'Meeting' date 2025-12-09 in xlsx is the consent execution date. Note: this is PRE 14C; if a DEF 14C was subsequently filed it would be the legally-final document.) [2026-04-29] phase5g: vote_source set DEF 14C acc=0001679788-25-000218 url=https://www.sec.gov/Archives/edgar/data/1679788/000167978825000218/coin-pre14cinformationstat.htm (written-consent transaction; reviewer: https://www.sec.gov/Archives/edgar/data/1679788/000167978825000218/coin-pre14cinformationstat.htm PRE 14C information statement filed 2025-12 confirming COIN reincorporation approved by majority shareholder written consent (no shareholder meeting). 'Meeting' date 2025-12-09 in xlsx is the consent execution date. Note: this is PRE 14C; if a DEF 14C was subsequently filed it would be the legally-final document.) [2026-04-29] phase5q: COIN meeting_date_iso 2025-12-09 -> 2025-11-04 (written-consent execution date, not a meeting date); vote_mechanism None -> WRITTEN_CONSENT; primary source: 8-K filed 2025-12-15 (acc 0001679788-25-000247) at https://www.sec.gov/Archives/edgar/data/1679788/000167978825000247/coin-20251215.htm stating 'On November 4, 2025, stockholders of the Company holding a majority of the voting power of outstanding capital stock approved the reincorporation' (written consent in lieu of meeting; consistent with PRE 14C/DEF 14C info statement structure); bug found 2026-04-29 via WebSearch validation pass (Tier-1 self-validation) [2026-04-29] phase5r: bucket 'C' -> 'B1' (DE->TX effective 2025-12-15 >= SB29 -> bucket B1) [2026-04-29] phase5t: row independently validated by external Reviewer A; bucket and key dates match current dataset (v3.55) [2026-04-29] phase5u: row independently validated by external Reviewer (full-residual pass, 78/276 substantive answers); validations applied: V_DATE_ANN=CONFIRM; V_BUCKET=WRONG=B1; 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: written-consent transaction; approval_pct NULL by design per protocol §3.7. Standard derived from DGCL §228. Per-firm consent threshold pincite pending PRE 14C / 8-K review.
[2026-04-29] v3.75: PINCITE-VERIFIED via PRE 14C acc 0001679788-25-000218: 'stockholders holding approximately 78.40% of the voting power approved the reincorporation via written consent on November 4, 2025.' Standard: DGCL §228 (action by written consent in lieu of meeting) requires holders of at least the minimum number of votes that would be necessary at a meeting — here, majority of voting power of outstanding shares.