Spinoff Tracker

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

Biohaven Pharmaceutical Holding Co Ltd. → Biohaven Ltd. BHVN

Distribution2022-10-03
Return+66.87%
ParentBiohaven Pharmaceutical Holding Co Ltd.
SpincoBiohaven Ltd. BHVN
StatusCompleted
StructureSpin-off A filing states a pro-rata distribution: holders receive shares automatically.
FocusNot focus-increasing Parent and spinco remain in the same industry; the separation divides scale rather than business.
Ratio1 Biohaven Ltd. share for every 2 Biohaven Pharmaceutical shares
Ratio noteDistributed immediately before Pfizer's acquisition of the remaining parent; the distribution was taxable to US holders.
Checked against EDGAR2026-08-22

Data trap

Shares distributed and shares outstanding differ here even though the parent retained nothing: 35,832,557 shares went out pro rata, while legacy options and restricted units settling the same day added a further 3,535,485, so 39,368,042 were outstanding. The BHVN ticker also changed company — the parent traded as BHVN until Pfizer's acquisition closed the same day and was then delisted, and the spinco took the symbol. Unlike almost every deal here the distribution was taxable to US holders, treated as a dividend rather than a tax-free separation.

The restated filings have landed; this is kept as history.

Catalyst clock

  1. 2022-05-10Separation announced
  2. 2022-08-10Form 10 filed
  3. 2022-09-20Form 10 last amended
  4. 2022-09-22Form 10 effective
  5. 2022-09-26Record date
  6. When-issued trading opens
  7. 2022-10-03Distribution
  8. 2022-11-09First standalone earnings
  9. Index inclusion announced

Performance since separation

Biohaven Ltd. since separation+66.87%
Biohaven Pharmaceutical Holding Co Ltd. over the same windownever listed separately
S&P 500 (SPY) over the same window+108.87%
Russell 2000 (IWM) over the same window+77.19%
Excess over the S&P 500-42.00%
Excess over the Russell 2000-10.32%

Measured from the first regular-way close on or after the distribution — 2022-10-04 at 8.30 — to 2026-08-21 at 13.85. Window: 3.9 years. The 2022-10-03 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.

Filings

Every fact on this page comes from one of these.

Notes

Biohaven Pharmaceutical separated its early-stage pipeline into a new company immediately before Pfizer acquired the remainder for cash. Holders received spinco shares automatically first, then had their remaining parent shares cashed out. Classified non-focus-increasing: both entities sat in pharmaceutical preparations.