MDU RESOURCES GROUP INC MDU → Knife River Corporation KNF
| Parent | MDU RESOURCES GROUP INC MDU |
|---|---|
| Spinco | Knife River Corporation KNF |
| 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 Knife River share for every 4 MDU Resources shares |
| Ratio note | The ratio covers the roughly 90 percent of Knife River distributed; MDU retained the balance. |
| Parent retains | 10% |
| Checked against EDGAR | 2026-08-22 |
Data trap
Two counting traps. MDU retained about 10 percent, so computing the spinco's share count as the parent's shares divided by four understates it by roughly a tenth. And the pre-separation quarterly report shows 1,000 shares outstanding on its cover — a shell figure from before the distribution, not a share count, and useless for any market-capitalisation calculation.
The restated filings have landed; this is kept as history.
Catalyst clock
- 2022-08-04Separation announced
- 2023-03-10Form 10 filed
- 2023-05-08Form 10 last amended
- 2023-05-10Form 10 effective
- 2023-05-22Record date
- 2023-05-25When-issued trading opens
- 2023-05-31Distribution
- 2023-08-08First standalone earnings
- —Index inclusion announced
Performance since separation
| Knife River Corporation since separation | +88.95% |
|---|---|
| MDU RESOURCES GROUP INC over the same window | +80.05% |
| S&P 500 (SPY) over the same window | +83.25% |
| Russell 2000 (IWM) over the same window | +72.62% |
| Excess over the S&P 500 | +5.70% |
| Excess over the Russell 2000 | +16.33% |
Measured from the first regular-way close on or after the distribution — 2023-06-01 at 35.02 — to 2026-08-21 at 66.17. Window: 3.2 years. The 2023-05-31 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 | -2.74% |
|---|---|
| Combined (MDU RESOURCES GROUP INC + Knife River Corporation), pre-distribution to now | +231.15% |
| Combined excess over the S&P 500 | +148.91% |
| Combined excess over the Russell 2000 | +160.23% |
Combined treats a pre-spin holding as 1 Knife River share for every 4 MDU Resources shares valued at the parent's last close before regular post-spin trading resumed — 2023-05-30 at 11.02 — 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.
- 10-12B/Afiled 2023-05-08 · 0001140361-23-023310Final Form 10 amendment; Ex-99.1 information statement carries the 1-for-4 ratio, the May 22 record date, the May 31 distribution and the 90 percent distribution
- 8-Kfiled 2023-05-12 · 0001140361-23-024280Stockholder letter restating the August 2022 announcement
- 8-Kfiled 2023-06-01 · 0001140361-23-027662Completion: distribution effective 11:59 p.m. Eastern on May 31, 2023; MDU retained approximately 10 percent
- 10-Qfiled 2023-08-08 · 0001955520-23-000014First post-separation periodic report; 56,566,214 shares outstanding
- 8-Kfiled 2023-08-08 · 0001955520-23-000010Item 2.02 first results release as an independent company
Notes
MDU Resources' separation of its construction-materials and aggregates business. The registrant Knife River Holding Company took the Knife River Corporation name at completion while the pre-existing subsidiary of that name became KRC Materials. Left unclassified: EDGAR gives both entities the same mining and quarrying code, which scores non-focus-increasing, but the parent is a diversified regulated utility and the spinco an aggregates producer. Classified focus_increasing: same rationale as MDU's later Everus spin — the Form 10 frames Knife River as completing MDU's shift to 'two pure-play publicly traded companies, one focused on regulated energy delivery and the other on construction materials.' Knife River is the fifth-largest sand-and-gravel producer in the US. It raised roughly $1.05 billion of new debt (notes, term loans, a revolver) largely to repay ~$684 million of related-party debt owed to MDU's Centennial subsidiary.