ILLUMINA, INC. ILMN → GRAIL, Inc. GRAL
| Parent | ILLUMINA, INC. ILMN |
|---|---|
| Spinco | GRAIL, Inc. GRAL |
| Status | Completed |
| Structure | Spin-off A filing states a pro-rata distribution: holders receive shares automatically. |
| Focus | Focus-increasing Parent and spinco operate in different industries — the class the research associates with stronger post-separation returns. |
| Ratio | 1 GRAIL share for every 6 Illumina shares |
| Ratio note | Whole shares only; no fractional shares were distributed. |
| Parent retains | 14.5% |
| Checked against EDGAR | 2026-08-22 |
Data trap
The pre-open effective time is misleading here, and in the opposite direction to Solventum. The distribution took effect at 12:01 a.m. Eastern on June 24, yet both companies' filings state regular-way trading only began on June 25 — so June 24 was still a when-issued session at roughly 611,000 shares against 10.4 million the next day. Two deals with near-identical pre-open effective times, opposite first regular-way dates, which is why trading volume rather than the stated effective time decides the anchor on this site. Note also that about 26.6 million shares were distributed against 31.0 million outstanding, because Illumina retained 14.5 percent.
The restated filings have landed; this is kept as history.
Catalyst clock
- 2023-12-17Separation announced
- 2024-05-06Form 10 filed
- 2024-06-03Form 10 last amended
- 2024-06-03Form 10 effective
- 2024-06-13Record date
- —When-issued trading opens
- 2024-06-24Distribution
- 2024-08-13First standalone earnings
- —Index inclusion announced
Performance since separation
| GRAIL, Inc. since separation | +367.88% |
|---|---|
| ILLUMINA, INC. over the same window | +104.80% |
| S&P 500 (SPY) over the same window | +41.08% |
| Russell 2000 (IWM) over the same window | +49.07% |
| Excess over the S&P 500 | +326.80% |
| Excess over the Russell 2000 | +318.81% |
Measured from the first regular-way close on or after the distribution — 2024-06-25 at 17.00 — to 2026-08-21 at 79.54. Window: 2.2 years. The 2024-06-24 session was skipped: it traded on when-issued volume, not regular-way, and pricing from it would measure the return against a market that no longer existed the next day. Two benchmarks, because one is misleading: spin-offs are usually small companies, and across this period small caps lagged the S&P by several points a year on their own. Measured against the S&P alone, roughly a third of any shortfall is company size rather than the separation. Returns are arithmetic over end-of-day closing prices. Unlike every other figure on this page, they do not come from a filing.
Pre-distribution investor return
| Parent, announcement to separation | -14.58% |
|---|---|
| Combined (ILLUMINA, INC. + GRAIL, Inc.), pre-distribution to now | +120.51% |
| Combined excess over the S&P 500 | +79.88% |
| Combined excess over the Russell 2000 | +70.79% |
Combined treats a pre-spin holding as 1 GRAIL share for every 6 Illumina shares valued at the parent's last close before regular post-spin trading resumed — 2024-06-21 at 105.51 — against that same basket today. That baseline is a practical proxy, not an attempt to isolate exactly how much value the separation transferred: for a large parent and a small spinco, ordinary day-to-day price noise can be bigger than the transfer itself. Run-up measures only the parent's own price, from the announcement date to that same baseline — how far the market had already moved before the separation's mechanics ever happened.
Filings
Every fact on this page comes from one of these.
- 10-12Bfiled 2024-05-06 · 0001193125-24-132022Initial Form 10 registration statement
- 10-12B/Afiled 2024-06-03 · 0001193125-24-152397Final Form 10 amendment; its information statement still leaves the record and distribution dates blank
- 8-Kfiled 2024-06-03 · 0001193125-24-153238Form 10 declared effective June 3, 2024; final information statement with the June 13 record date, the June 24 distribution and regular-way trading from June 25
- 8-Kfiled 2024-06-03 · 0001193125-24-153239Illumina board approval confirming the 1-for-6 ratio and the same dates from the parent side
- 8-Kfiled 2024-06-24 · 0001193125-24-167037Completion: pro rata distribution of 85.5 percent effective 12:01 a.m. Eastern on June 24, 2024; Illumina retained 14.5 percent
- 10-Qfiled 2024-08-13 · 0001628280-24-036965First periodic report; 31,049,148 shares issued and outstanding
Notes
Illumina's separation of GRAIL, the cancer-screening business it had acquired and was then ordered to divest by the European Commission — so the retained stake here is a regulatory ceiling rather than a financing choice. Classified focus-increasing: Illumina returns to sequencing instruments while GRAIL is a clinical testing laboratory.