Stone Ridge Holdings Group

Stone Ridge Holdings Group (SRHG) was founded in 2012. Its website identifies Ross Stevens as founder and CEO and Yan Zhao as co-founder, president and head of the investment committee. Operating companies include Stone Ridge Asset Management, NYDIG and Longtail Re.⁠[1][2][3]

NYDIG began in 2017 with capabilities developed for Stone Ridge’s bitcoin investments and treasury holdings, later serving outside clients. On October 13, 2020, the group announced a purchase of over 10,000 bitcoin, then worth over $100 million, as a principal treasury-reserve component. NYDIG executed and custodied the purchase.⁠[4]

In his 2025 investor letter, Ross Stevens described founding Longtail Re in 2020 to partner with underwriters on reinsurance and invest the resulting float in Stone Ridge-originated fixed-income assets. The letter said Longtail completed a $1.4 billion retrospective reinsurance transaction with Everest Group in November 2025 and ended the year with over $6 billion in assets.⁠[5]

On December 14, 2020, MassMutual and Stone Ridge announced an agreement for MassMutual to acquire Flourish for undisclosed terms. Flourish served registered investment advisers with digital products, including the Flourish Cash service operated by Stone Ridge Securities LLC.⁠[6]

Flourish Financial LLC’s 2021 financial statements record that the company, formerly Stone Ridge Securities LLC, was acquired by MassMutual on February 1, 2021 and became its indirect wholly owned subsidiary.⁠[7]

The December 2025 investor letter said SRHG completed primary equity financing that year led by an unnamed U.S.United StatesThe United States is a federal country in North America made up of 50 states, the District of Columbia as the seat of government, and territories such as Puerto Rico and Guam; its capital is Washington, D.C. The Continental Congress adopted the Declaration of Independence on July 4, 1776. The 2020 census (April 1, 2020) counted a resident population of 331,449,281, and the 435 seats of the House of Representatives are apportioned among the states on the basis of the census.Open the full entry mutual financial-services company. It disclosed cumulative primary equity raised by the parent and affiliates of $4.6 billion.⁠[5]

On August 27, 2026, BitGoBitGoBitGo is an American digital asset custody and infrastructure company founded in 2013 by Mike Belshe. It offers custody, wallets, staking, trading, financing, stablecoin and settlement services, and its subsidiary BitGo Bank & Trust, National Association, is a national trust bank regulated by the Office of the Comptroller of the Currency. The company listed on the New York Stock Exchange under the ticker BTGO in January 2026 and is the custodian and infrastructure provider for World Liberty Financial’s USD1 stablecoin.Open the full entry announced completion of its acquisition of NYDIG’s institutional trading business. NYDIG continued focusing on bitcoin mining, high-performance computing and power infrastructure. Its website described working alongside Stone Ridge Energy, whose owned and operated assets accounted for roughly 3% of U.S. natural-gas production.⁠[8][9]

SRHG’s website listed $36 billion in assets under management as of October 31, 2026, and more than $7 billion invested in its strategies by the firm’s balance sheet, employees and equity owners.⁠[1]

Stone Ridge Asset Management serves insurers, institutions and registered investment advisers across reinsurance, energy, opportunistic investing, single-family housing, alternative lending, multi-strategy, art and bond-ladder ETFs. NYDIG develops power and compute infrastructure, while Longtail Re provides diversified reinsurance.⁠[3]

The website listed Paul Germain as president of Stone Ridge Asset Management; Mike Sapnar as head of insurance solutions and CEO of Longtail Re; Tomer Seifan as head of Stone Ridge Energy and group CFO; Tejas Shah as investment-committee member and NYDIG CEO; and Jim Rothwell as head of legal.⁠[2]

The group’s stated criteria for new businesses include building products its own team would use, avoiding a model dependent on others losing, evaluating principal-agent problems, and having access to sustainably valuable proprietary data.⁠[10]