# Billy Quinn (William J. Quinn)
William J. Quinn, known as Billy Quinn, is an American energy private-equity investor who founded [Pearl Energy Investments](https://www.edgepedia.org/pearl-energy-investments), a Dallas-based firm focused on North American upstream oil and gas, and serves as its Managing Partner.[1](https://www.pearl-energy.com/team/billy-quinn) He is best known for nearly two decades at Natural Gas Partners (NGP), described as Co-Managing Partner in some sources, where he helped grow the firm from a $100 million fund into a $10.5 billion franchise, and for leading Pearl's investments in companies including [Permian Resources](https://www.edgepedia.org/permian-resources), Infinity Natural Resources, and SLANT Energy, on whose boards he sits.[1](https://www.pearl-energy.com/team/billy-quinn) • [2](https://magazine.wharton.upenn.edu/issues/fall-2014/billy-quinn-w92/)
| Fact | Detail |
|---|---|
| Role | Founder and Managing Partner, Pearl Energy Investments (Dallas), founded 2015[3](https://ir.infinitynaturalresources.com/governance/board-of-directors/person-details/default.aspx?ItemId=0aa2311d-6553-4e26-b678-d7a805545c3a) • [1](https://www.pearl-energy.com/team/billy-quinn) |
| Prior career | Co-Managing Partner, Natural Gas Partners, for almost 20 years; earlier Rainwater, Inc., Hicks, Muse, Tate and Furst, Bear Stearns, BT Securities[1](https://www.pearl-energy.com/team/billy-quinn) • [2](https://magazine.wharton.upenn.edu/issues/fall-2014/billy-quinn-w92/) |
| Education | B.S.E. in Finance with honors, Wharton (W'92); M.B.A., Stanford GSB[1](https://www.pearl-energy.com/team/billy-quinn) • [2](https://magazine.wharton.upenn.edu/issues/fall-2014/billy-quinn-w92/) |
| Pearl Fund III | $720 million, launched September 2021, per Quinn's own statement on the Powers Podcast[4](https://www.powerspod.com/billy-quinn-founder-pearl-energy-navigating-the-high-stakes-world-of-energy-private-equity/) |
| Deal size focus | Sub-$100 million transactions, including deals as small as $400,000–$500,000[5](https://finance.yahoo.com/news/money-talks-permian-thriving-small-143229315.html) |
| Permian Resources stake | 9,245,584 shares with sole voting power per the September 19, 2025 Schedule 13D/A (~1.3% of 702,730,246 Class A shares outstanding)[6](https://whalewisdom.com/filing/quinn-william-j-sc-13da-2025-09-19-pr) |
| Board seats | Permian Resources (since September 2022), Infinity Natural Resources, SLANT Energy; formerly Spring Valley Acquisition Corp (Chairman, 2021–22)[3](https://ir.infinitynaturalresources.com/governance/board-of-directors/person-details/default.aspx?ItemId=0aa2311d-6553-4e26-b678-d7a805545c3a) • [1](https://www.pearl-energy.com/team/billy-quinn) |
## Career and education
Quinn graduated from the [Wharton School](https://www.edgepedia.org/wharton-school) of the University of Pennsylvania in 1992 with a B.S.E. in Finance, with honors, and later earned an M.B.A. from the Stanford University Graduate School of Business, where he now guest-lectures on private equity investing.[1](https://www.pearl-energy.com/team/billy-quinn)
He began his career as an analyst in the investment banking divisions of [Bear Stearns](https://www.edgepedia.org/bear-stearns) & Co. and BT Securities Corporation, then moved to the buy side at Rainwater, Inc. and Hicks, Muse, Tate and Furst, Inc.[1](https://www.pearl-energy.com/team/billy-quinn) In a 2014 Wharton Magazine interview he explained the move: "What I didn't like about investment banking was that you had no real ownership of the businesses that you were involved with."[2](https://magazine.wharton.upenn.edu/issues/fall-2014/billy-quinn-w92/)
In 1995 he joined Natural Gas Partners, which had been incubated in investor Richard Rainwater's office, and worked out an arrangement to remain a partner at NGP while attending Stanford business school. He later rejoined full time and, in his words, helped build NGP "from a small $100 million fund to a multibillion-dollar private equity franchise."[2](https://magazine.wharton.upenn.edu/issues/fall-2014/billy-quinn-w92/) [The Carlyle Group](https://www.edgepedia.org/the-carlyle-group) acquired a stake in NGP in 2012, and Quinn stepped down as managing partner of the $10.5 billion firm effective December 31, 2014.[2](https://magazine.wharton.upenn.edu/issues/fall-2014/billy-quinn-w92/)
In the fall of 2014 he observed that most energy private-equity funds then being raised were $2–6 billion vehicles and described himself as "a seller, not a buyer" of such funds, investing his own money in the interim through BQ Capital Partners across energy, real estate, and other businesses.[2](https://magazine.wharton.upenn.edu/issues/fall-2014/billy-quinn-w92/) His NGP title is described slightly differently across sources: the firm's team page says Co-Managing Partner for almost 20 years, while [Infinity Natural Resources](https://www.edgepedia.org/infinity-natural-resources)' board biography says Managing Partner; the record does not resolve the difference.[1](https://www.pearl-energy.com/team/billy-quinn) • [3](https://ir.infinitynaturalresources.com/governance/board-of-directors/person-details/default.aspx?ItemId=0aa2311d-6553-4e26-b678-d7a805545c3a)
## Pearl Energy Investments: thesis and funds
Quinn founded Pearl Energy Investments in 2015 and is responsible for all aspects of managing the firm.[3](https://ir.infinitynaturalresources.com/governance/board-of-directors/person-details/default.aspx?ItemId=0aa2311d-6553-4e26-b678-d7a805545c3a) • [1](https://www.pearl-energy.com/team/billy-quinn) The firm targets North American upstream oil and gas companies, deliberately working below the deal sizes where large-cap energy funds compete. Quinn has described the focus as deals under $100 million, including transactions as small as $400,000 or $500,000, a category he says holds "lots of deals ... and possibly some better value opportunities."[5](https://finance.yahoo.com/news/money-talks-permian-thriving-small-143229315.html)
On fund size, Quinn stated on the Powers Podcast that Pearl's third fund was a $720 million vehicle launched in September 2021; this is his own account and is not independently corroborated in the record.[4](https://www.powerspod.com/billy-quinn-founder-pearl-energy-navigating-the-high-stakes-world-of-energy-private-equity/) Deal selection, he says, is "driven by the management team and their specific competitive advantage in what they do," not by a macro thesis, and Pearl is unlikely to be competitive above $100 million on Tier 1 acreage.[5](https://finance.yahoo.com/news/money-talks-permian-thriving-small-143229315.html) Pearl's Permian exposure spans four companies: Permian Resources, Powderhorn Energy Partners, Swordfish Energy, and Slant Energy, each looking at different asset types and sizes.[5](https://finance.yahoo.com/news/money-talks-permian-thriving-small-143229315.html) Hart Energy reported that Quinn and his team hunkered down to emerge not only capable of surviving the one-two punch of demand destruction from COVID and the ESG movement, but to thrive, with the article's headline citing a 250% ROI.[7](https://www.hartenergy.com/exclusives/qa-pearl-energy-investments-rides-downturns-250-roi-212110/)
## Notable investments and boards
**Permian Resources (NYSE: PR).** Quinn has been a director of Permian Resources Corporation since September 2022.[3](https://ir.infinitynaturalresources.com/governance/board-of-directors/person-details/default.aspx?ItemId=0aa2311d-6553-4e26-b678-d7a805545c3a) According to his Schedule 13D/A filed September 19, 2025, he held sole voting and dispositive power over 9,245,584 shares, about 1.3% of the 702,730,246 Class A shares then outstanding, comprising 1,312,429 Class A shares plus 7,933,155 shares issuable on conversion of Units and Class C common stock.[6](https://whalewisdom.com/filing/quinn-william-j-sc-13da-2025-09-19-pr)
**Spring Valley Acquisition Corp. / NuScale Power (NYSE: SMR).** From September 2021 until May 2022, Quinn served as a director and Chairman of Spring Valley Acquisition Corporation, which became NuScale Power Corporation following its May 2022 business combination.[3](https://ir.infinitynaturalresources.com/governance/board-of-directors/person-details/default.aspx?ItemId=0aa2311d-6553-4e26-b678-d7a805545c3a)
**Infinity Natural Resources (NYSE: INR).** Quinn is a director and 10% owner of Infinity Natural Resources, a Pearl portfolio company operating in the Marcellus and Utica shales.[8](https://www.filingexplorer.com/insider-trades/0001193125-26-271065) • [4](https://www.powerspod.com/billy-quinn-founder-pearl-energy-navigating-the-high-stakes-world-of-energy-private-equity/) A Form 4 filed June 15, 2026 shows an aggregate Pearl-controlled equity position of about 28,960,732 shares after Quinn's own June 11, 2026 purchase of 11,497 Class A shares at $13.20 (about $151,750).[8](https://www.filingexplorer.com/insider-trades/0001193125-26-271065)
**SLANT Energy.** The Pearl team page lists Quinn on SLANT Energy's board among the firm's portfolio companies.[1](https://www.pearl-energy.com/team/billy-quinn) The retrieved record does not detail what the company does or when Pearl invested.
## What his trading record shows since 2024
SEC Form 4 filings trace Quinn's direct trading in Permian Resources. He bought an initial direct stake of 312,429 shares at $12.79 (about $4.0 million) on September 10, 2024, then added 1,000,000 shares at $12.10–$12.83 (about $12.6 million) in March 2025.[9](http://openinsider.com/insider/Quinn-William-J/1377293) In March 2026 he sold 800,000 shares at $19.15 (about $15.32 million) and 512,429 shares at $19.59 (about $10.04 million), a combined roughly $25.4 million, reducing his position at prices near 50% above his 2024–25 purchase levels.[9](http://openinsider.com/insider/Quinn-William-J/1377293) The 13D/A of September 2025, between the buying and selling periods, showed 9,245,584 shares under his sole voting power.[6](https://whalewisdom.com/filing/quinn-william-j-sc-13da-2025-09-19-pr) At Infinity Natural Resources, his June 2026 open-market purchase followed the IPO-period buildup of the Pearl-controlled position of about 29 million shares.[8](https://www.filingexplorer.com/insider-trades/0001193125-26-271065)
## References
1. [Billy Quinn | Pearl Energy Investments](https://www.pearl-energy.com/team/billy-quinn)
2. [Pride of Private Equity: Billy Quinn (Wharton Magazine, Fall 2014)](https://magazine.wharton.upenn.edu/issues/fall-2014/billy-quinn-w92/)
3. [Infinity Natural Resources — Board of Directors: William J. Quinn](https://ir.infinitynaturalresources.com/governance/board-of-directors/person-details/default.aspx?ItemId=0aa2311d-6553-4e26-b678-d7a805545c3a)
4. [#330 – Billy Quinn – Founder @ Pearl Energy (Powers Podcast)](https://www.powerspod.com/billy-quinn-founder-pearl-energy-navigating-the-high-stakes-world-of-energy-private-equity/)
5. [Money Talks: Permian Thriving on Small Deals, Says Pearl Energy (Hart Energy via Yahoo Finance)](https://finance.yahoo.com/news/money-talks-permian-thriving-small-143229315.html)
6. [Quinn William J Schedule 13D/A Concerning Permian Resources Corp, 2025-09-19 (WhaleWisdom)](https://whalewisdom.com/filing/quinn-william-j-sc-13da-2025-09-19-pr)
7. [Q&A: Pearl Energy Investments Rides the Downturns for 250% ROI (Hart Energy)](https://www.hartenergy.com/exclusives/qa-pearl-energy-investments-rides-downturns-250-roi-212110/)
8. [SEC Form 4 — William J. Quinn, Infinity Natural Resources, filed June 15, 2026 (Filing Explorer)](https://www.filingexplorer.com/insider-trades/0001193125-26-271065)
9. [Quinn William J — SEC Form 4 Insider Trading Screener (OpenInsider)](http://openinsider.com/insider/Quinn-William-J/1377293)
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*Topic: Encyclopedia › Society and history › Economics and business › Founders, operators, and investors › Venture and growth investors › Deep-tech, climate, and hard-tech investors*
*Initially written Sep 17, 2026 · Edited: Oct 11, 2026; Oct 15, 2026; Oct 21, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license