ArcBest Corp. (ARCB) — Reincorporation detail

Why this firm matters

Standard cohort firm (Completed). Included for breadth across destinations and sectors.

Controller & ownership

Diffuse / non-controlled

Diffuse institutional (FMR/Fidelity 5.8% largest) holds approximately 5.8% of voting power. No single holder reaches the controlled-company threshold (>50% of voting power).

Source: Schedule 13G filings 2026; DEF 14A 2026

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.

ArcBest's announcement-day move was a non-event

**Bottom line.** All four ways of looking at ArcBest's stock that day point to roughly the same answer: fell modestly by about 1.0%, and the move was statistically indistinguishable from a normal trading day (p = 0.73).

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

**Bottom line.** ArcBest'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 ArcBest'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.

ArcBest sits near the middle of the 36-firm cohort

**Bottom line.** ArcBest's announcement-day reading is close to the cohort-wide mean of +0.69%. Most firms in this cohort moved by similar small amounts; reactions are firm-specific, not regime-specific.

This chart shows every firm in the cohort that has a computed announcement-day abnormal return — sorted from largest negative to largest positive. ArcBest 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: 2026-02-20 · Estimation window: 2025-03-07 to 2026-02-19 (240 days)

Specification	Day-0 AR	Inference
Synthetic control (19-donor Industrials peer pool)i	-0.75%	no inference
Market model (SPY benchmark)i	-1.30%	Patell-z p-value = 0.656
Sector-augmented model (SPY + Industrials ETF (XLI)) HEADLINEi	-0.96%	Patell-z p-value = 0.726
Matched pair (vs FDX, market-model-adjusted)i	-1.82%	two-sided p-value = 0.583
Raw differential vs FDXi	-1.40%	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 +0.0039% per day in the pre-event window (p = 0.244). 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: 8 of 19 peer firms moved in the same direction as the treated firm on the event day (binomial p = 0.6476). — 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 = 0.842 (good tracking); R² = 0.662 (fraction of pre-event variance explained); Durbin-Watson = 2.15 (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: 2026-04-24 · 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	+0.60%	Patell-z p-value = 0.826

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	-3.25%	Market-model benchmark (S&P 500)
Pooled three-event statistici	+7.00%	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 = 0.726, 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.arcb.com/
EDGAR — https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0000894405&type=&dateb=&owner=include&count=40
Proxy — https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0000894405&type=DEF+14A&dateb=&owner=include&count=40
EDGAR accession (canonical) — 0001104659-26-020485

Classification & audit trail

Bucket

B1

Panel eligibility

PANEL_A_post_SB29

Audit status

VERIFIED_EDGAR

Source confidence

VERIFIED_EFFECTIVE

Transaction status

COMPLETED

Audit notes

Effective date present but no Accession URL in v6 rev78; retrieve from EDGAR.
v2.9: status CLAIMED_COMPLETED_UNVERIFIED — eff_date present but EDGAR URL missing; reclassify to COMPLETED after 8-K verification
v2.9.2: promoted to VERIFIED_EDGAR + COMPLETED — ArcBest Corp — Confirmed in BLP April 2026 update; reincorporation DE→TX completed (DEF 14A March 13, 2026)
[2026-04-28] Phase 4I: replaced Google-search IR fallback with direct URL https://investor.arcb.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 0001104659-26-048553 (2026-04-24, Δ=1d) applied from EDGAR pull (status=AUTO_RESOLVED) [2026-04-28] phase5e: cleaned edgar_accession_canonical: extracted '0001104659-26-020485' from raw value '000110465926020485 (PRE 14A)' (source=unhyphenated_normalized) [2026-04-28] phase5c: vote source 8-K 0001104659-26-048553 (2026-04-24, Δ=1d) applied from EDGAR pull (status=AUTO_RESOLVED) [2026-04-29] phase5r: bucket 'C' -> 'B1' (DE->TX effective 2026-04-24 >= SB29 -> bucket B1) [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=B1; 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: 13.9M for / 6.9M against / 17,901 abstain / 675,343 broker non-votes. ~67% of votes cast; majority-of-outstanding test also met. Special meeting Apr 24, 2026; effective May 15, 2026.