Spinoff Tracker

Every US corporate spin-off, sourced from the filing that proves it.

Exelon Corporation EXC → Constellation Energy Corporation CEG

Distribution2022-02-01
Return+414.77%
ParentExelon Corporation EXC
SpincoConstellation Energy Corporation CEG
StatusCompleted
StructureSpin-off A filing states a pro-rata distribution: holders receive shares automatically.
FocusFocus-increasing Parent and spinco operate in different industries — the class the research associates with stronger post-separation returns.
Ratio1 Constellation share for every 3 Exelon shares
Checked against EDGAR2026-08-22

Data trap

The distribution took effect at 12:01 a.m. Eastern on February 1, but the whole of that session still traded on when-issued volume — roughly 299,000 shares against 23.9 million the next day. A day-zero return computed off February 1 prices the wrong market. Separately, every Exelon figure for a period before the separation includes the competitive generation business, and Constellation's own 2021 annual report covers a year when it was still an Exelon subsidiary.

Still live.

Catalyst clock

  1. 2021-02-24Separation announced
  2. 2021-12-08Form 10 filed
  3. 2021-12-20Form 10 last amended
  4. 2021-12-29Form 10 effective
  5. 2022-01-20Record date
  6. When-issued trading opens
  7. 2022-02-01Distribution
  8. 2022-05-12First standalone earnings
  9. Index inclusion announced

Performance since separation

Constellation Energy Corporation since separation+414.77%
Exelon Corporation over the same window+6.16%
S&P 500 (SPY) over the same window+69.05%
Russell 2000 (IWM) over the same window+47.50%
Excess over the S&P 500+345.72%
Excess over the Russell 2000+367.27%

Measured from the first regular-way close on or after the distribution — 2022-02-02 at 53.01 — to 2026-08-21 at 272.88. Window: 4.6 years. The 2022-02-01 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 separationprice history starts after the separation
Combined (Exelon Corporation + Constellation Energy Corporation), pre-distribution to now+226.09%
Combined excess over the S&P 500+155.90%
Combined excess over the Russell 2000+177.03%

Combined treats a pre-spin holding as 1 Constellation share for every 3 Exelon shares valued at the parent's last close before regular post-spin trading resumed — 2022-01-31 at 41.32 — 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.

Filings

Every fact on this page comes from one of these.

Notes

Exelon's separation of Constellation, its competitive power generation arm, leaving Exelon a pure regulated transmission and distribution utility. Focus-increasing on any reading: the two halves have different customers, different regulation and different risk. Exelon retained nothing.