Private Equity Firm Databases Compared: PitchBook, Preqin, Axial and PE Firm Index

PE Firm Index, PitchBook, Preqin and Axial each answer a different version of the question of which private equity firms are active in a sector. PE Firm Index is a public-source directory of mid-market and lower-middle-market firms and their portfolio companies, PitchBook provides private market data and software covering companies, deals, investors and funds, and Preqin, part of BlackRock, provides alternative assets data. Axial runs a private deal network for North American lower middle market M&A, debt and minority equity transactions, so it suits people who are working on a transaction.

• PE Firm Index is built for sector research on mid-market and lower-middle-market private equity, with 227 firms listed in October 2026 and sector pages that show firm and portfolio company counts.
• PitchBook suits teams that need one platform for market intelligence, deal sourcing, due diligence, fundraising, benchmarking and portfolio management across companies, deals, investors and funds.
• Preqin, part of BlackRock, suits readers whose questions sit in alternative assets data, solutions and insights.
• Axial suits professionals who own, advise or invest in North American companies with $5M to $250M in revenue and $500K to $25M in EBITDA and want to take part in deals through a private network.

1. PE Firm Index: researching mid-market PE firms by sector

PE Firm Index is a public-source directory of private equity firms, their portfolio companies and sectors, focused on mid-market and lower-middle-market private equity. In October 2026 PE Firm Index listed 227 private equity firms, each built from publicly available firm and portfolio information (fund announcements, firm websites, press releases and similar public records).

The sector pages are where most readers start, because they answer the question of who is active in a given industry with counts attached. PE Firm Index covers healthcare, industrials, business services, financial services, consumer, energy and education, and in October 2026 the pages showed the following:

• Healthcare: 77 firms and 408 portfolio companies.
• Industrials: 29 firms and 175 portfolio companies.
• Business services: 23 firms and 190 portfolio companies.
• Financial services: 52 firms and 141 portfolio companies.

A banker building a buyer list for a healthcare services company, or a job seeker looking for operating roles at industrials-focused sponsors, can use those pages to see which firms hold portfolio companies in the sector before going deeper on any one of them. PE Firm Index also publishes market maps of private equity firms and PE-backed portfolio companies by strategy and sector, and a working directory of lower-middle-market PE firms for readers who work in that segment specifically.

For ongoing coverage, PE Firm Index publishes The PE Firm Index Brief, a weekly newsletter of public-source intelligence on PE firms, portfolio companies, sector activity, operator moves and mid-market value creation signals. Readers who track a sector over months rather than for a single project tend to use the newsletter alongside the directory.

On sourcing and independence, PE Firm Index is maintained by Mario Peshev, and the businesses he founded appear in it only under Advisors, each with an ownership disclosure. PE Firm Index states that its profiles, research and rankings favour no client or related party, that no position is for sale and that it publishes no reviews. It publishes its methodology for sourcing, reviewing and labelling public information, and it accepts corrections and additions from firms and operators, so a firm that finds an outdated portfolio entry can submit an update at pefirmindex.com.

2. PitchBook: private market data across companies, deals, investors and funds

PitchBook provides private market data, research and tools through the PitchBook Platform, a suite of software applications covering companies, deals, investors and funds. The breadth of record types means a user can move from a portfolio company to the investor behind it and the fund that made the investment within the same PitchBook Platform.

PitchBook lists market intelligence, deal sourcing, due diligence, fundraising, benchmarking and portfolio management among the uses of its platform. That range suits investment teams, corporate development groups and advisors who want one system to support several stages of their work, from finding targets to comparing fund performance.

3. Preqin: alternative assets data

Preqin, part of BlackRock, describes itself as a provider of alternative assets data, solutions and insights. Private equity sits within alternative assets, so Preqin is a source readers consult when their research question is framed around the asset class as a whole.

Preqin suits allocators, fund managers and analysts whose work spans alternative assets and who want data, solutions and insights from a single provider. Readers who already work within the BlackRock ecosystem may also find it a familiar starting point.

4. Axial: North American lower middle market deal network

Axial describes itself as an M&A platform for professionals who own, advise and invest in North American lower middle market businesses. Axial operates as a private deal network for M&A, debt and minority equity transactions involving companies with $5M to $250M in revenue and $500K to $25M in EBITDA.

Axial suits business owners, M&A advisors, lenders and investors who are actively working on transactions in that size range. Because the network is organised around deals within defined revenue and EBITDA bands, it is most useful to readers whose next step is a conversation about a specific company.

How to choose between them: a private equity database comparison

The four sources overlap less than their names suggest, so the useful way to compare them is to start from the question you need answered and the record type that answers it. A buyer can check each source against the following criteria before committing time to it.

1. Market segment. If your work sits in mid-market or lower-middle-market private equity, PE Firm Index and Axial are focused on that segment, with Axial defining its range at $5M to $250M in revenue and $500K to $25M in EBITDA. PitchBook and Preqin cover private markets and alternative assets more broadly.
2. Record type. Decide whether you need firm and portfolio company lists (PE Firm Index), records spanning companies, deals, investors and funds (PitchBook), alternative assets data (Preqin) or live transaction activity (Axial).
3. Research versus transaction. Readers building a target list or preparing for interviews need a research source, while readers with a company to sell, finance or buy in North America may get further with Axial's deal network.
4. Sector depth. Check how many firms and portfolio companies a source shows in your sector. On PE Firm Index the October 2026 figures ranged from 23 firms in business services to 77 firms in healthcare, which gives a sense of how far a sector list will reach.
5. Sourcing and corrections. If you need to know where each record came from, look for a published methodology and a way to submit corrections. PE Firm Index publishes both, along with ownership disclosures for its maintainer's businesses.
6. Workflow coverage. Teams that want one system for sourcing, diligence, fundraising, benchmarking and portfolio management should look at the uses PitchBook lists for its platform.

Many teams use more than one of these, for example PE Firm Index for an initial sector map of mid-market sponsors and PitchBook or Preqin for deal and fund detail on the firms that make the shortlist.

Frequently asked questions

How do private equity databases compare?

Private equity databases compare most clearly by the record type each one is built around. PE Firm Index is a public-source directory of mid-market and lower-middle-market PE firms and their portfolio companies, PitchBook covers companies, deals, investors and funds, and Preqin provides alternative assets data. Axial is a private deal network for lower middle market transactions in North America.

What are PitchBook alternatives for private equity research?

Readers looking at PitchBook alternatives usually choose based on scope. Preqin, part of BlackRock, provides alternative assets data, solutions and insights, while PE Firm Index offers a public-source directory focused on mid-market and lower-middle-market firms, with sector pages and market maps. Axial is an option for professionals who want access to lower middle market deal activity through a private network.

Which source covers lower-middle-market private equity firms?

PE Firm Index publishes a working directory of lower-middle-market PE firms as well as sector pages for healthcare, industrials, business services, financial services, consumer, energy and education. Axial also focuses on the lower middle market, organised around transactions involving companies with $5M to $250M in revenue and $500K to $25M in EBITDA.

Can a firm correct its profile on PE Firm Index?

PE Firm Index accepts corrections and additions from firms and operators, and it publishes its methodology for sourcing, reviewing and labelling public information. PE Firm Index states that no position is for sale and that it publishes no reviews, so a correction updates the public record without affecting where a firm appears.