What actually happens after a merger is announced

1,619 deals announced between 2012-01-04 and 2026-08-03, each one resolved against the SEC filing that ended it — a Form 25, 25-NSE or 15. Not against a share price, and not against a news story.

49 days median time from announcement to delisting, across 1,545 completed deals. The mean is 127 days.

That gap is the first thing worth knowing. The mean is 2.6 times the median, because a small number of deals take years — the slowest here took 3,983 days. Quoting one average would misdescribe almost every deal in the set, so here is the distribution instead.

Where deals actually land

Time to close	Deals	Share
under a month	87	5.6%
1-2 months	816	52.8%
2-3 months	175	11.3%
3-6 months	252	16.3%
6-12 months	125	8.1%
over a year	90	5.8%

909 of 1,545 completed deals (59%) were done within 60 days. 88 (5.7%) took more than a year. Percentiles: 10th 32, 25th 36, 75th 105, 90th 226, 99th 1629 days.

By year announced

Year	Announced	Completed	Stale	Median days
2012	93	92	1	38
2013	121	121	0	42
2014	101	101	0	50
2015	127	123	4	55
2016	141	139	2	56
2017	124	121	3	55
2018	119	114	5	56
2019	115	112	3	48
2020	76	74	2	62
2021	131	124	7	52
2022	118	116	2	56
2023	51	51	0	43
2024	114	106	8	48
2025	124	114	2	49
2026	64	37	0	40

A median is only shown where at least ten deals from that year completed. The most recent years are incomplete by construction: a deal announced this quarter has not had time to resolve, which is why 35 are marked pending rather than counted.

Three things this does not say

It is not a success rate. Every deal here reached a merger proxy or a tender document. A deal that collapses during negotiation never files one and never appears, so 97.5% is the share of deals that got that far with delisting evidence behind them — not the share of merger talks that end in a merger, which this data cannot see.

Stale is not broken. 39 deals show no Form 25 or 15 within 400 days of announcement. That is the absence of an event. Some of those are dead deals and some are slow ones, and nothing in the filings distinguishes them.

Prices are as filed, and sometimes stated once. 1,425 deals carry an announced price; 48 of them state it exactly once in the document, which means nothing in the filing corroborates it.

Corrections made to this dataset

Published because the corrections are more informative than the numbers:

offer price (WBD) — $30.00 was an unsolicited bid of 8 Dec 2025, rejected, recounted in the proxy's negotiation history. The extractor matched a correctly-formed sentence describing a superseded price. Stated only once, so the ambiguity check saw no conflict. Agreed price is $31.00, stated twice in the merger agreement, plus a $0.25/quarter ticking fee accruing daily after 30 September.
classification rule — An ACQUIRER files its own DEFM14A so shareholders can approve issuing stock, then survives the merger and never delists. Every acquirer was therefore scored a broken deal. Corrected by classifying target vs acquirer from the filing's own language with an explicit UNCLASSIFIED margin rather than a keyword hit.
section boundary — The first occurrence of a heading in a filing is the table-of-contents entry, not the section. Caused two separate extraction bugs; one over-correction then dropped 6 of 16 deals.

How to check any of this

Every deal carries the SEC accession number of the filing that announced it and the form that resolved it. Both are public. Pick a row, look it up, and see whether this page is telling the truth — which is the only reason to believe a track record at all.