Introduction
On a sponsor's books, a buy-and-build is one investment; in a bank's deal log, it can be twenty transactions. The platform, the first company bought, goes through the fund's investment committee and is paid for with fund equity and new acquisition debt. The add-ons that follow are usually bought by the platform itself, with its own cash flow and borrowing capacity, so most of the strategy's deals never reach the fund as new investments. PitchBook's Q2 2026 US private equity breakdown estimated 885 add-ons, roughly three-quarters of US buyouts, while platform buyouts fell 34% to 289 as sponsors added to existing companies rather than underwrite new platforms needing fresh leverage. From the coverage seat, a platform is a stream of mandates: the purchase, add-on sales and financings, a refinancing, and the exit of the combined business.
Platform and Add-On: Two Purchases on Different Terms
The two deals differ less in size than in decision rights: who approves, whose money pays, and which bank products each one uses.
What Makes a Company a Platform
A platform is chosen for what it can absorb: a management team able to run acquisitions alongside the business, finance systems that can take in another company's books, and a leading position in a fragmented market with many small owners. The capital structure is part of the choice, because an acquisition financing sized with room to grow turns the credit agreement into the add-on budget, the mechanics set out in add-on financing. The sponsor pays a full multiple because platforms are usually sold through competitive auctions, and the price includes the pipeline every bidder expects to buy afterwards.
Why Add-Ons Cost Less
Add-on sellers are often founders and families, advised by a small mergers and acquisitions (M&A) firm or by nobody. Their businesses carry key-person risk, thinner reporting and few buyers able to finance them. The platform offers certainty, an operator in the same industry and often rollover equity that lets the founder share in the larger company. Because it can count on cost savings a stand-alone buyer cannot, it can outbid that buyer and still pay well below its own multiple. The difference shows in how each deal reaches a bank:
| Platform | Add-on | |
|---|---|---|
| Who approves | Fund investment committee | Platform board, with sponsor sign-off |
| Equity | Fund capital, sometimes co-investors | Company cash; occasionally fresh fund equity |
| Debt | New acquisition financing | Incremental or delayed-draw debt |
| Seller | Corporate or sponsor, in an auction | Founder or family, small adviser |
| Bank work | Buy-side or sell-side advice, underwriting | Target's sell-side, incremental debt |
Any fresh equity comes from the fund's follow-on reserves, so even a fund past its investment period keeps building, as the fund lifecycle from the coverage seat explains.
Multiple Arbitrage and Where It Stops Working
Multiple arbitrage is the arithmetic behind add-ons: earnings bought at a small-company multiple are valued at the platform's multiple when the combined company is sold. The healthcare guide's platform and add-on article covers the mechanics, and the three value creation levers in a leveraged buyout its place beside growth and paydown. The hold-period gauge is the blended entry multiple.
- Blended Entry Multiple
The total price paid for a platform and its add-ons divided by their combined EBITDA at purchase. It falls with every add-on bought below the platform's multiple, and its gap to the expected exit multiple is the arbitrage a buy-and-build is counting on.
Take a platform with $40 million of EBITDA bought at 11x, or $440 million, and add-ons contributing $20 million of EBITDA at 7x, or $140 million. The blended multiple is about 9.7x. Sold at 11x, the combined $60 million is worth $660 million, a gain of $80 million before any growth. If the exit buyer credits the add-on earnings at only 8x, the value falls to $600 million and the gain to $20 million.
Integration Decides the Exit Multiple
The re-rating is earned. An exit buyer's quality of earnings review tests whether the add-ons run on one set of systems, report as one company and keep their customers, and it strips pro forma adjustments for savings not yet achieved. A platform that has bought faster than it has integrated looks like a holding company of small businesses and is priced closer to their multiples. Add-on prices also rise as rival platforms chase the same targets.
Investment committees probe the exit multiple for that reason, as how sponsors evaluate a deal describes.
Serial Acquisitions and Antitrust
Many add-ons fall below the Hart-Scott-Rodino (HSR) filing threshold, but Guideline 8 of the 2023 Merger Guidelines lets the Federal Trade Commission (FTC) and the Department of Justice (DOJ) examine a firm's pattern or strategy of multiple acquisitions in related business lines and weigh its cumulative effect, and both agencies said in February 2025 that they would keep applying those guidelines. The FTC's anesthesia roll-up case against a sponsor is covered in FTC antitrust enforcement in healthcare. In a concentrated local market, an add-on screen should show the platform's cumulative share beside each price.
Where the Bank Earns Across a Buy-and-Build
A buy-and-build produces fee events at every stage, but not all of them reach the coverage bank that knows the platform best.
The Platform Purchase and Its Financing
The platform is what most banks pitch for: advice to the seller or the sponsor, and the acquisition financing, underwritten by banks or provided by direct lenders. Lenders in the platform's debt often get the first look at incremental tranches, and a delayed-draw term loan committed at closing pre-funds add-ons that then need no separate financing. How a sponsor pays for buy-side work on a platform, and whether it pays for any on add-ons, varies by firm, as set out in buy-side advisory for sponsors.
Add-On Sell-Sides and Sourcing
The add-ons are where the volume sits and where a large bank is least likely to be paid. Many targets are sold by lower middle market advisers and regional boutiques, or directly to the platform. A bank can still earn its place with a sector map: the remaining independents, their owners and their likely timing.
- Proprietary Deal
An acquisition negotiated directly between buyer and seller without a competitive auction. Add-ons are often sourced this way, the platform offering speed, certainty and a role for the founder in exchange for a lower multiple.
When a target is large enough for an auction, the platform becomes one bidder in someone else's sale, and the sponsor's coverage bank may be advising the seller.
Add-On Financing, Refinancing and the Exit
Each add-on uses the platform's debt capacity, usually tested on pro forma EBITDA that credits the acquired earnings. Once the company outgrows its facility, the sponsor refinances, and a larger borrower can move from a private credit unitranche to syndicated loans or bonds at a lower spread, the work in refinancings and repricings for portfolio companies. The last event is the exit of the combined company, sized for buyers that would never have looked at its parts, the route weighed in the sponsor exit decision framework.
Core & Main: A Completed Buy-and-Build
Clayton, Dubilier & Rice (CD&R) bought its platform from a corporation, the classic source covered in the carve-out playbook. On August 1, 2017, it completed the carve-out of HD Supply's Waterworks business for $2.5 billion: a water-infrastructure distributor with 244 branches in 46 states, renamed Core & Main. Later filings trace the build:
| Date | Event | Stage of the build |
|---|---|---|
| Aug 2017 | Carve-out from HD Supply | Platform purchase and financing |
| Jul 2019 | Long Island Pipe Supply acquired | Add-on, one of the largest in the company's history |
| Mar 2020 | R&B Co. acquired | Add-on, one of the largest in the company's history |
| Jul 2021 | Initial public offering (IPO) at $20 a share | Listing and refinancing |
| Jan 2022 | Secondary offering of 20 million shares at $26 | Sponsor sell-down |
| Jan 2024 | Final secondary offering and company repurchase | CD&R fully exited |
The January 2022 offering prospectus counts 16 acquisitions since 2017, adding about $645 million of pre-acquisition annual net sales, yet credits organic growth with over two-thirds of 13.4% compound annual net sales growth from fiscal 2017 to the twelve months to October 2021. It also records the IPO refinancing: a new $1.5 billion seven-year term loan replaced $1,257.8 million of the prior one, $300 million and $750 million of senior notes were redeemed, and the asset-based revolver grew to $850 million.
The exit was a staged sell-down rather than one sale, the route examined in sponsor-backed IPOs from the coverage seat, and Core & Main's annual report for fiscal 2023 records that the CD&R investors held no shares as of January 25, 2024. The listing was where the arbitrage was tested: investors priced a national distributor, not a collection of acquired branches, and the July 2021 prospectus backed that with 12 acquisitions integrated in the prior 15 quarters. Every add-on and refinancing during a hold is a bet on that final pricing, and a bank's work across the build becomes the record that lets the last buyer treat many purchases as one company.
