The Merger Deal Spread and Its Components

A company trading at $40 announces it is being acquired for $50 a share in cash. You might expect the stock to jump straight to $50. Instead it jumps to $47 and sits there until the deal closes months later. That $3 gap is not a mistake — it is the market pricing in everything that could still go wrong between "announced" and "closed."

What the spread compensates for

Between announcement and closing — often four to twelve months for a straightforward deal, much longer for one facing antitrust scrutiny — a merger arbitrageur who buys the target stock is exposed to several distinct risks, and the spread is compensation for carrying all of them at once:

Risk	What can go wrong
Regulatory	Antitrust authorities block or delay the deal, or demand divestitures that change its value
Financing	The acquirer's debt or equity financing falls through before closing
Shareholder vote	Target or acquirer shareholders vote down the deal
Material adverse change	A clause lets the buyer walk away if the target's business deteriorates sharply
Time value	Capital is tied up until closing; every extra month of delay costs a arbitrageur the opportunity to redeploy that cash

Worked example

A stock trades at $40 before the announcement. The acquirer offers $50 cash per share, and the market prices the target at $47 the day after announcement, with the deal expected to close in six months.

• Deal spread: $50 - 47 = 3$, i.e. $3, or 6.4 percent of the $47 purchase price.
• Annualized return if the deal closes: roughly $6.4\% \times (12/6) \approx 12.8\%$ a year — a meaningfully higher yield than a six-month Treasury bill, which is the market's way of paying the arbitrageur for taking on deal risk.
• What the spread implies about deal probability: if the stock would fall back to its pre-deal $40 on a break, and the market is pricing a fair bet, a $3 spread out of a possible $10 gain-versus-$7 loss implies roughly a 70 percent chance of the deal closing and a 30 percent chance it breaks — investors can back out an implied probability from the spread this way, even though the true odds are never directly observable.

What moves the spread

The spread narrows as uncertainty resolves — a favorable antitrust ruling, a shareholder vote passing, financing confirmed — and it widens sharply on bad news. A single headline that a regulator has opened an in-depth investigation can blow a 6 percent spread out to 20 percent overnight, because the market suddenly assigns real odds to the deal breaking. If a deal does break, the target's stock typically falls hard, often most of the way back toward its pre-announcement price, since the takeover premium disappears along with the deal.