XOMA Royalty Corporation (XOMA) — Reincorporation detail

Why this firm matters

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

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.

XOMA Royalty's stock rose sharply the day the move was announced

**Bottom line.** XOMA Royalty rose sharply by 4.0% 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 = 0.20).

This chart shows four different statistical lenses on what XOMA Royalty'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 XOMA Royalty, the announcement-day move was on the edge of its normal range

**Bottom line.** XOMA Royalty's announcement-day reading sits noticeably away from its average — but within the spread of moves the stock already produces in normal trading.

This histogram shows every daily move XOMA Royalty'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.

XOMA Royalty is one of the cohort's larger positive reactions

**Bottom line.** XOMA Royalty's reading sits in the positive tail of the cohort distribution. Cohort-wide mean is +0.69%; reactions vary widely by firm-specific factors, not destination state.

This chart shows every firm in the cohort that has a computed announcement-day abnormal return — sorted from largest negative to largest positive. XOMA Royalty 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: 2025-04-04 · Estimation window: 2024-04-19 to 2025-04-03 (240 days)

Specification	Day-0 AR	Inference
Synthetic control (20-donor Health Care peer pool)i	+2.99%	no inference
Market model (SPY benchmark)i	+4.04%	Patell-z p-value = 0.244
Sector-augmented model (SPY + Biotech ETF (XBI)) HEADLINEi	+4.04%	Patell-z p-value = 0.198
Matched pair (vs MDT, market-model-adjusted)i	+8.53% ^***	two-sided p-value = 0.013
Raw differential vs MDTi	+3.83%	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 -0.0038% per day in the pre-event window (p = 0.219). 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: 20 of 20 peer firms moved in the same direction as the treated firm on the event day (binomial p = 0.0000). — 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 = 0.194 (weak tracking — interpret with caution); R² = -0.531 (fraction of pre-event variance explained); Durbin-Watson = 2.36 (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: 2025-05-30 · 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	-2.82%	Patell-z p-value = 0.379

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: 2025-05-30 · n_post = 230 days

Buy-and-hold abnormal returns (BHAR)

Horizon & benchmark	BHAR	Inference
1 month vs S&P 500	+1.28%	Patell-z = +0.21 · p = 0.836 · n = 21 days
1 month vs sector ETF (XLV)	+2.82%	Patell-z = +0.21 · p = 0.836 · n = 21 days
3 months vs S&P 500	+21.37%	Patell-z = +0.90 · p = 0.370 · n = 63 days
3 months vs sector ETF (XLV)	+27.03%	Patell-z = +0.90 · p = 0.370 · n = 63 days
6 months vs S&P 500	+13.15%	Patell-z = +0.55 · p = 0.583 · n = 126 days
6 months vs sector ETF (XLV)	+9.80%	Patell-z = +0.55 · p = 0.583 · n = 126 days

Calendar-time portfolio alpha (CTE)

Specification	Annualized alpha	Inference
Calendar-time portfolio alpha vs S&P 500	+32.82%/yr	t = +0.57 · p = 0.567 · n = 230 days · Newey-West HAC SE (lag=5)
Calendar-time portfolio alpha vs sector ETF	+55.23%/yr	t = +0.86 · p = 0.391 · n = 230 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 = 0.198, 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://www.xoma.com/investors
EDGAR — https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0000791908&type=&dateb=&owner=include&count=40
Proxy — https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0000791908&type=DEF+14A&dateb=&owner=include&count=40
EDGAR accession (canonical) — 0001193125-25-179446

Classification & audit trail

Bucket

B2

Panel eligibility

PANEL_A_post_SB29

Audit status

VERIFIED

Source confidence

VERIFIED_VOTE

Transaction status

COMPLETED

Audit notes

Phase 3F: cleared future meeting_date_iso=2026-05-21 — firm already moved (eff_date=2025-09-26); the future date was the next annual meeting at the new domicile, not the reincorporation vote.
Phase 3F vote-result inferred APPROVED from status=COMPLETED + populated eff date (2025-09-26). Original vote_result was 'SCHEDULED'. Verify with 8-K if uncertain.
[2026-04-28] Phase 4I: replaced Google-search IR fallback with direct URL https://www.xoma.com/investors
[2026-04-28] Phase 4K: corrected year error (announcement 2026-03-19 -> 2025-04-04). Annual meeting 2025-05-21 adjourned to 2025-05-28; eff 2025-05-30 via certificate of conversion. Source: 8-K 2025-08-13 (acc 0001193125-25-179446).
[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] Phase 4T (v3.32 reviewer follow-up): cleared audit_status PENDING_TRANSACTION -> VERIFIED. 8-K accession 0001193125-25-179446 (filed 2025-08-13) populated; documents reincorporation effective 2025-05-30 per 8-K Item 5.03. [2026-04-29] phase5r: bucket 'D' -> 'B2' (DE->NV effective 2025-05-30 >= SB29 -> bucket B2) [2026-04-29] phase5w: comprehensive validation by external reviewer across tranches v3 (4-version full residual walk, 269 substantive answers across 52 firms, 0 bucket drifts vs v3.58)
[2026-04-29] v3.75: PINCITE-VERIFIED via 8-K — XOMA Royalty. Annual meeting May 21, 2025 (adjourned to May 28, 2025). Item 5.07 tally: 2,956,575 for / 73,597 against / 20,134 abstain / 1,089,301 broker non-votes (97% of votes cast). Effective May 30, 2025. DGCL §266 conversion to Nevada.