JACOBS SOLUTIONS INC. J → Amentum Holdings, Inc. AMTM
| Parent | JACOBS SOLUTIONS INC. J |
|---|---|
| Spinco | Amentum Holdings, Inc. AMTM |
| 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 Amentum share for every 1 Jacobs share |
| Ratio note | Jacobs holders received shares pro rata without tendering; the spinco then merged with Amentum, so the distributed shares are about half the post-merger share count. |
| Parent retains | 7.5% |
| Checked against EDGAR | 2026-08-22 |
Data trap
A Reverse Morris Trust, so the share counts do not behave like an ordinary spin-off. Jacobs holders received 124,084,108 shares — about 51 percent of the 243,302,173 outstanding after the immediately following merger with Amentum. A further 37 percent went to Amentum's existing owner and 4.5 percent sat in escrow against fiscal-2024 profit targets. The retained-stake figure also has two denominators: Jacobs kept up to 19.9 percent of the spinco before the merger, which diluted to 7.5 percent of the combined company. 7.5 is the post-separation figure and the one recorded here.
The restated filings have landed; this is kept as history.
Catalyst clock
- 2023-11-20Separation announced
- 2024-07-15Form 10 filed
- 2024-09-13Form 10 last amended
- 2024-09-18Form 10 effective
- 2024-09-23Record date
- 2024-09-24When-issued trading opens
- 2024-09-27Distribution
- 2024-12-16First standalone earnings
- —Index inclusion announced
Performance since separation
| Amentum Holdings, Inc. since separation | -33.36% |
|---|---|
| JACOBS SOLUTIONS INC. over the same window | +16.66% |
| S&P 500 (SPY) over the same window | +33.99% |
| Russell 2000 (IWM) over the same window | +36.14% |
| Excess over the S&P 500 | -67.35% |
| Excess over the Russell 2000 | -69.50% |
Measured from the first regular-way close on or after the distribution — 2024-09-30 at 32.25 — to 2026-08-21 at 21.49. Window: 1.9 years. The 2024-09-27 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 | +12.88% |
|---|---|
| Combined (JACOBS SOLUTIONS INC. + Amentum Holdings, Inc.), pre-distribution to now | +34.15% |
| Combined excess over the S&P 500 | +0.35% |
| Combined excess over the Russell 2000 | -2.91% |
Combined treats a pre-spin holding as 1 Amentum share for every 1 Jacobs share valued at the parent's last close before regular post-spin trading resumed — 2024-09-26 at 127.89 — 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 2024-07-15 · 0001193125-24-178835Initial Form 10 registration statement, filed as Amazon Holdco Inc.
- 10-12B/Afiled 2024-09-13 · 0001193125-24-218486Final amendment; Ex-99.1 information statement carries the pro rata 1-for-1 distribution, the September 23 record date and the 4:05 p.m. Eastern September 27 distribution
- 8-Kfiled 2024-09-18 · 0001193125-24-221432Form 10 declared effective September 18, 2024; when-issued from about September 24, regular-way from September 30
- 8-Kfiled 2024-10-03 · 0000950157-24-001361Completion: pro rata distribution without consideration; 243,302,173 shares outstanding, 124,084,108 distributed to Jacobs holders, 18,247,663 retained
- 8-Kfiled 2024-12-16 · 0002011286-24-000064Item 2.02 first results release as an independent company
Notes
Jacobs separated its Critical Mission Solutions business, which merged with Amentum immediately after the distribution. Despite the Reverse Morris Trust structure the shareholder leg was a genuine pro-rata spin-off, not an exchange offer: Jacobs holders received shares automatically and kept their Jacobs stock. The distribution took effect at 4:05 p.m. Eastern, after the close, so regular-way trading began the next session. Classified focus-increasing: Jacobs retained consulting and infrastructure while the government-services business left.