Not to be confused with Tides Network, a related nonprofit in the nexus
The Tides Nexus is a collection of related left-of-center grantmaking, fiscal sponsorship, and advocacy nonprofits headquartered in San Francisco, California. The system originated in 1976 when liberal political activist Drummond Pike joined with Jane Lehman, heiress to the Reynolds family tobacco fortune, to form the Tides Foundation to offer novel services to liberal donors interested in funding political activism and the creation of new activist groups.
The Tides Foundation pioneered “fiscal sponsorship” (or “incubation”), a process in which a sponsor organization is paid to act as an umbrella under which new center-left political groups may fundraise and operate prior to achieving recognition of tax-exempt status from the Internal Revenue Service (IRS), at which point they’re often spun off into standalone nonprofits. In 1996, Tides passed its fiscal sponsorship services to a separate nonprofit, the Tides Center.
The Tides Foundation has also become a major pass-through funder on the Left thanks in large part to its use of donor-advised funds (DAFs), a kind of charitable “savings account” in which donors make grants to Tides, which invests the money and passes it on to other (typically left-leaning) nonprofits at the original donors’ direction.
The Tides Nexus (a blanket term covering all associated groups) has since grown to incorporate eight nonprofits, including various supporting entities, investment management nonprofits, a 501(c)(4) advocacy group, and a single controlling organization (the Tides Network). This page briefly describes each member and its respective role in the Tides Nexus; more information can be found on each member’s InfluenceWatch profile.
Leadership and Key People
Drummond Pike is the co-founder of Tides, although he has since retired from the organizations. A veteran political activist, Pike began his career in 1970 as associate director for the now-defunct Youth Project in Washington, D.C., a group formed to give young people with inherited wealth a way to channel donations. 
While Pike did not develop donor-advised funds himself (DAFs have been used by community foundations since the early 20th century), the Youth Project’s model of guiding funding from individual donors to nonprofit political causes reportedly inspired the creation of the Tides Foundation in 1976, which utilized DAFs to encourage individuals to donate to Tides since they would hold an advisory role in its grantmaking.  Funding for the project came from Jane Lehman, heiress to the fortune generated by the Reynolds tobacco conglomerate and an ex-president of the center-left Arca Foundation. In 1979, Pike extended Tides’ services to incubating new liberal nonprofits (or “projects”), a system known as fiscal sponsorship. 
Pike resigned his leadership of the Tides organizations in 2010. He has been a board member for numerous left-progressive organizations outside of the Tides Nexus, including the Democracy Alliance, Enlyst Fund, JK Irwin Foundation, Underdog Foundation, Island Press, Institute for New Economic Thinking, Environmental Working Group, Endswell Foundation, Working Assets, Network for Good, Sage Centre, Threshold Foundation, and Charity Projects Entertainment Fund, Groundspring, Social Venture Network, Sierra Fund, and America’s Charities. 
Chief Executive Officer
The Tides Network is a 501(c)(3) nonprofit formed in 2005.  The Network serves as the hub for other groups in its orbit, providing management services to the nonprofits in exchange for service fees, from which it derives the bulk of its revenues. The Network also pays for the salaries and compensation expenditures of related Tides organizations.
Consequently, the Tides Network serves as the controlling entity for three more 501(c)(3) nonprofits in the Tides Nexus: the Tides Foundation, the system’s primary pass-through funder; the Tides Center, the system’s fiscal sponsorship nonprofit; and Tides Inc. (TINC). 
The Tides Foundation is the primary 501(c)(3) grantmaking and pass-through nonprofit in the Tides Nexus as well as the oldest Tides organization, established in 1976 in California by Drummond Pike and Jane Lehman, heiress to the Reynolds tobacco fortune and an ex-president of the center-left Arca Foundation.
The Tides Foundation is a major provider of donor-advised funds (DAFs), a kind of charitable “savings account” in which donors gift funds to grow in Tides’ investment accounts before advising Tides to pay out the funds in grants to other (typically left-leaning) nonprofits. In 2018, the group paid out $291 million in grants. 
The Tides Foundation was one of the first nonprofits to offer paid fiscal sponsorship (or incubation) services to spawn new center-left political groups, many of which are major advocacy organizations for the American political left today. Notable groups incubated by the Tides Foundation include People for the American Way (PFAW), which lobbies for liberal judges and legislation, and the Natural Resources Defense Council (NRDC), a leading environmentalist lobby.  However, Tides’ incubation services were spun off in 1996 into the Tides Center, a separate nonprofit.
The Tides Center is the leading 501(c)(3) fiscal sponsorship nonprofit in the Tides Nexus, spun off from the Tides Foundation in 1996 to handle its paid incubation services. The Tides Center operates as an umbrella group, providing 501(c)(3) coverage to groups that are in the process of receiving recognition of tax-exempt status from the IRS or that do not intend to spin off as independent nonprofits. In effect, projects incubated by the Tides Center inherit its 501(c)(3) tax-exempt status, allowing them to accept tax-deductible contributions prior to being spun off as an independent organization.  This has the added effect of obscuring the donors to these individual projects, as grants to incubated organizations are paid to the Tides Center.
Tides Advocacy (formerly Tides Advocacy Fund, The Advocacy Fund, and Tsunami Fund) is the sole 501(c)(4) advocacy nonprofit in the Tides Nexus, formed in 1992. The group parallels the Tides Foundation in providing pass-through funding to other 501(c)(4) nonprofits on the political left as well as the Tides Center in fiscally sponsoring new 501(c)(4) projects. Few of Tides Advocacy’s donors are known; however, between 2013 and 2018 the Tides Foundation paid $23.8 million in grants to Tides Advocacy, mainly in support of various Tides Advocacy-sponsored projects.
Tides Advocacy’s Form 990 filing for 2018 indicates that the Tides Network, the primary controlling entity in the Tides Nexus, is an “affiliated” but “unrelated” nonprofit according to the legal definition of related organizations described by the IRS.  Tides Advocacy’s leadership and board of directors also overlaps with that of other Tides organizations.
Tides Inc. (TINC)
Tides Inc. (TINC) is a 501(c)(3) supporting nonprofit which manages Tides Converge, an office space rented to the other Tides organizations as well as a number of left-progressive organizations on San Francisco’s historic Presidio grounds. 
Harding Rock Fund
The Harding Rock Fund is a 501(c)(3) nonprofit controlled by the Tides Foundation. The Fund exists solely to manage the Tides Foundation’s assets; consequently, changes to its board of directors and articles of incorporation are entirely controlled by the Tides Foundation. 
Tides Two Rivers Fund
The Tides Two Rivers Fund is a 501(c)(3) nonprofit controlled by the Tides Foundation and the Tides Center. Like the Harding Rock Fund, the Two Rivers Fund provides grantmaking and asset management services to its “sister” nonprofits, which control the group’s board of directors. 
Tides Canada Foundation
The Tides Canada Foundation is a Vancouver, Canada-based nonprofit associated with the Tides organizations in San Francisco. Despite its name, Tides Canada is an IRS-designated 501(c)(3) public charity and files annual Form 990 reports in the United States; it is also registered as a “public foundation” in Canada.
The Tides Canada Initiatives Society is a Canadian nonprofit closely associated with Tides Canada; in 2018, all of Tides Canada’s grants went to fund Tides Canada Initiatives Society.  The group’s primary activity involves “programs focused on environmental conservation, education and research, leadership development, civic engagement, capacity building and social welfare programs.”