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L.4 · ADVANCED · 3 MIN

Merger Arbitrage: Spread Capture in Announced Deals

Merger arbitrage is the trade of going long the target and (in a stock-deal) short the acquirer once a merger is announced, capturing the spread between the current price and the deal value at closing. The mechanic is simple; the practice is where the alpha lives. The whole asset class exists in the gap between 'this deal will probably close' and 'this deal will definitely close.' That gap is the spread. Suitability note: merger arbitrage is a professional strategy presented here for literacy — the spreads are thin, the tail risk of a broken deal is fat, and retail execution costs typically consume the edge.

Quiz · 5 questions ↓

Deal types and their spread components

Deal typeSpread componentRisk profile
All-cash dealFixed cash price; spread = ($deal price - target price) / target pricePure deal-completion risk; cleaner to model
All-stock deal (fixed ratio)Exchange ratio determines value; spread depends on acquirer share priceAdd long-short pair risk (acquirer + target price correlation)
Cash-and-stock collarFloor/ceiling on stock portion; complex value calculationMultiple risk vectors -- highest skill threshold
Hostile / contestedWider spread reflecting deal uncertaintyAntitrust + shareholder-approval + financing risk concentrated
Reverse Morris Trust / inversionsTax-driven structure; deal value depends on tax outcomeTax-rule-change risk + spinoff-merger combined complexity

Why the break fee is the key number

The single most-important number in merger arb is the BREAK FEE -- the contractually-disclosed amount the target must pay the acquirer if the deal fails. Break fees typically run 1-3% of deal value. A LARGE break fee (say, 4%+ of deal value) signals the target board's confidence and creates economic incentive to resist competing bids. A SMALL break fee (under 1%) signals the target board kept optionality. Merger arbs read break fees carefully; the market often misprices the signal.

Antitrust risk as the unpriced spread

Antitrust risk is often the largest unpriced spread component in deals in concentrated industries. Enforcement intensity shifts with FTC and DOJ leadership: the early-2020s cycle produced an unusually high challenge rate (Visa-Plaid, Microsoft-Activision, JetBlue-Spirit), and spreads in pharma, big-tech, and concentrated-industry deals widen or narrow as the prevailing agency posture changes — even when both boards have approved. Reading the HSR antitrust filings is the merger-arb edge most retail investors skip.

Calculate and annualize a deal spread

Find a recently-announced cash merger on the platform's news view. Calculate the deal spread: (deal price - current target price) / current target price. Annualize by dividing by months-to-close and multiplying by 12. The annualized number is the implied risk premium; if it's above 8-10% the market is pricing real deal-fail risk.

The retail arb's structural disadvantages

Retail merger arb has STRUCTURAL DISADVANTAGES vs institutional arbs. Pros: brokerage cost is similar at retail vs institutional scale on liquid names. Cons: (1) institutional arbs read SEC filings within minutes; retail reads them next day; (2) merger-arb funds carry deal-broken positions across hundreds of deals so single-deal failures don't impair the portfolio -- retail concentrating in one deal eats the full downside; (3) shorting the acquirer in stock deals requires margin + locate -- not always available at retail.

Merger arbitrage in review

So far

Merger arb captures the deal spread between announcement and closing. The spread compensates for time value + residual deal-fail risk. Break fees and antitrust filings are the key signals to read. Retail can play arb on liquid deals but should diversify across multiple deals to absorb single-deal failures.

Check your understanding

Sit with the ideas.

An announced cash-and-stock merger trades at a 4% deal spread two months before expected closing. Antitrust filings are routine, both boards have approved, financing is committed. What is the dominant driver of that 4% spread?

Why:
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Other lessons in this course.

  1. 01Spin-Offs: The Forced-Selling Mispricing
  2. 02Capital Structure Arbitrage
  3. 03Short Selling Mechanics and the Squeeze
  4. 04Merger Arbitrage: Spread Capture in Announced Deals— reading now
  5. 05Stub Trading: Equity Slivers After Cash-Out Events
  6. 06Post-Reorganization Equity: Fresh-Start Accounting
  7. 07Busted IPOs: Capturing the Lockup-Expiry Bottom
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