Buy and Build: The Mechanics of Multiple Arbitrage Through Add-On Acquisitions
How PE firms create value by acquiring small companies at low multiples and integrating them into a larger platform that exits at a premium.
Buy-and-build is the most common value creation strategy in mid-market PE. The math is elegant: buy a platform at 8x EBITDA, bolt on smaller companies at 5-6x, and exit the combined entity at 9-10x. The arbitrage between entry and exit multiples, multiplied across several add-ons, generates significant returns.
The Math Behind Multiple Arbitrage
Consider a platform acquisition: - Platform: $20M EBITDA acquired at 8.0x = $160M enterprise value - Add-on 1: $5M EBITDA at 5.0x = $25M - Add-on 2: $4M EBITDA at 5.5x = $22M - Add-on 3: $3M EBITDA at 5.0x = $15M
Total EBITDA: $32M. Total invested: $222M (blended 6.9x). Exit at 9.0x: $288M. That's $66M of value created purely from the multiple gap — before any organic growth or synergies.
Why Small Companies Trade at Lower Multiples
- Size matters in valuation. Smaller companies trade at discounts because of:
- Customer concentration: a $5M EBITDA business often depends on 3-5 key customers
- Key-person risk: the founder IS the business
- Limited scalability: no systems, no middle management, no institutional processes
- Buyer pool: fewer acquirers compete for small deals, suppressing valuations
By absorbing these businesses into a larger platform with diversified revenue, professional management, and scalable infrastructure, you eliminate the discount factors — and the exit multiple reflects the larger, more institutional entity.
Execution Challenges
- The strategy sounds clean on paper. In practice:
- Integration fatigue: acquiring 5+ businesses in 3 years strains management and operations teams
- Culture clash: each acquired company has its own DNA. Forcing a uniform culture too fast destroys the value you just bought
- ERP migration: consolidating 6 different accounting systems onto one platform is an 18-month project minimum
- Revenue synergy mirage: cross-selling rarely works as modeled. Track record on this is poor
- Talent retention: founders who sold often leave after their earnout. Key employees follow
The Platform Company Thesis
A successful buy-and-build starts with the right platform: - Strong management team with M&A integration experience - Scalable back-office (finance, HR, IT) that can absorb bolt-ons - Clear geographic or service-line whitespace for expansion - Culture of standardization and measurement
Accretion/Dilution Math
When a 10x platform acquires a 5x add-on, the deal is immediately accretive to the blended multiple. But this only creates value if the exit multiple reflects the combined entity's scale. If the market still views it as a collection of small businesses stitched together, you won't capture the arbitrage.
Interview Angle
"Buy-and-build creates value through three levers: multiple arbitrage from buying small and exiting large, cost synergies from centralizing back-office functions, and revenue growth from expanded geographic coverage. The key risk is integration — if the platform can't absorb the add-ons operationally, you've bought complexity, not scale."