Largest CIT Providers Ranked by Publicly Disclosed Assets

A source-backed ranking of the largest collective investment trust providers using the latest public asset disclosures we verified as of June 24, 2026.

Largest CIT Providers Ranked by Publicly Disclosed Assets

Collective investment trusts keep gaining share in retirement plans, but many "largest CIT provider" lists online still blur the line between recordkeepers, asset managers, and the trust companies that actually serve as trustees or administrators for CITs. This version is tighter. We ranked providers by the latest publicly disclosed CIT or trust-related asset figures we could verify from official sources, and we call out where disclosure dates or methodologies differ.

If you are comparing retirement plan vendors more broadly, you can also review our guides to largest 401(k) recordkeepers, 401(k) plan advisors, and retirement plan benchmarks.

Largest CIT providers we could verify publicly

  1. Great Gray — $318.6 billion in fund assets as of March 31, 2026. Great Gray also notes that more than 9% of the reported total is held in fund-of-fund structures where it serves at both levels.

  2. SEI Trust Company — $260B+ in AUM as of September 30, 2025, according to SEI's January 27, 2026 investor relations press release.

  3. Reliance Trust — $57B+ in CIT assets, plus 100+ separately sponsored CITs and 14,500+ participating plans according to its public CIT solutions product sheet.

1. Great Gray

Great Gray appears to be the largest CIT provider we could verify from an official public disclosure. Its homepage states $318.6 billion in fund assets as of March 31, 2026. That makes Great Gray the clearest current No. 1 in this ranking based on publicly available figures.

One nuance matters: Great Gray also notes that more than 9% of the reported total is held in fund-of-fund structures where it is trustee or administrator at both levels. That does not invalidate the disclosure, but it is exactly the kind of footnote readers should understand before comparing firms line by line.

For plan committees, that scale can matter because larger CIT platforms often have broader operating relationships across recordkeepers, asset managers, and trading platforms. If you are evaluating operational fit alongside investment structure, our article on changing 401(k) recordkeepers can help frame the implementation side of the decision.

2. SEI Trust Company

SEI Trust Company ranks second in this source-backed list. In a January 27, 2026 SEI investor relations press release, the company says that as of September 30, 2025, SEI is an industry-leading third-party independent trustee of CIT services with $260B+ in AUM.

That figure is especially useful because it is specific to SEI's CIT trustee business, not just enterprise-wide assets. It also matches the role many retirement plan professionals associate with SEI: a large third-party trust and operating platform serving asset managers and plan sponsors in the CIT market.

For sponsors comparing CIT usage against other investment vehicle decisions inside a defined contribution lineup, it can also help to review adjacent plan design topics like stable value funds and broader 401(k) plan structures.

3. Reliance Trust

Reliance Trust ranks third based on the latest public figure we could verify. Its CIT solutions product sheet reports $57B+ in CIT assets. The same sheet also gives more operating context, including 100+ separately sponsored CITs and 14,500+ participating plans.

That additional plan-count context is helpful because total assets alone do not tell you everything about a CIT trustee's footprint. A provider with smaller total assets may still have meaningful market penetration, broad distribution relationships, or a particularly active lineup architecture.

If you are benchmarking plan costs or lineup structure while considering CIT adoption, our retirement plan benchmark pages can be a useful companion resource.

Alta Trust deserves a scale mention, but not an AUM rank

Alta Trust is worth mentioning because it publishes operating-scale stats that show real CIT market presence. On its CIT page, Alta says it works with 500+ fund families and 40+ retirement platforms, and elsewhere on the same page highlights 5000+ plans.

We did not rank Alta in the list above because the page does not publicly disclose a total CIT asset figure we could use for an apples-to-apples AUM ranking. Including Alta as a callout rather than forcing it into the ranking keeps the methodology cleaner.

Why CIT rankings are hard to compare

CIT rankings sound straightforward, but they are messy in practice. Different firms disclose different metrics, and they do not always do it on the same date or on the same basis.

That is why we would treat this page as a ranking of the largest publicly disclosed CIT providers, not a perfect census of the entire market.

What matters beyond asset size

If you are choosing a CIT provider or evaluating a trust platform for a retirement plan lineup, asset size is only one variable. Other factors often matter just as much:

Those issues often show up alongside the broader provider search. If you are still working through the plan marketplace itself, our best 401(k) providers and largest recordkeepers pages may be useful next reads.

Bottom line

Based on the latest official public figures we could verify as of June 24, 2026, the clearest asset-based CIT ranking is:

  1. Great Gray — $318.6 billion in fund assets

  2. SEI Trust Company — $260B+ in AUM as of September 30, 2025

  3. Reliance Trust — $57B+ in CIT assets

Alta Trust also shows meaningful scale through platform and plan-count disclosures, but without a public AUM number we did not include it in the ranked list.

As more trust companies publish current CIT asset figures, this ranking should get better. For now, these are the largest providers we could rank confidently from official source material rather than recycled secondary lists.

Sources