--- title: "OCIO 13F Filings: Outsourced-CIO Asset Allocation Decoded" type: learn slug: ocio-13f-cambridge-russell-mercer-aon-reading-guide canonical_url: https://13finsight.com/learn/ocio-13f-cambridge-russell-mercer-aon-reading-guide published_at: 2026-05-15T05:59:11.768Z updated_at: 2026-05-15T05:59:15.330Z author: Sarah Mitchell author_title: Education Editor author_url: https://13finsight.com/authors/sarah-mitchell word_count: 879 locale: en source: 13F Insight --- # OCIO 13F Filings: Outsourced-CIO Asset Allocation Decoded > Cambridge Associates' Q1 2026 13F is $6.31 billion entirely in ETFs. Russell Investments, Mercer, Aon, and BlackRock OCIO file similar structures. These are outsourced-CIO institutional asset allocations, not stock-picker books. Here's how to read them. The outsourced-CIO (OCIO) industry has grown into a meaningful share of institutional asset management over the past decade. OCIO providers — investment consulting firms that take discretionary management authority over client portfolios — manage approximately $2.5 trillion globally according to recent industry estimates. The largest OCIO providers include Cambridge Associates, Russell Investments, Mercer, Aon, BlackRock OCIO, Goldman Sachs Asset Management OCIO, and Northern Trust Asset Management. Each files a 13F covering their US-equity holdings exceeding $100 million in the discretionary client portfolios. The position lists look unlike anything a conventional active or passive equity manager files — they read as standardized asset-allocation building blocks, typically dominated by ETFs.Cambridge Associates' Q1 2026 13F is the cleanest example: $6.31 billion entirely in ETFs, no individual stocks. The top 10 is Vanguard VOO at 26.24%, Vanguard VT at 18.88%, Vanguard VEA at 9.75%, Vanguard VTI at 8.83%, plus six other Vanguard ETFs covering Treasuries, TIPS, emerging markets, and short-term Treasuries. Reading this filing as a discretionary stock-picker output is a category error. It is strategic-asset-allocation implementation, not security selection.What an OCIO actually doesOCIO providers take discretionary management authority over client portfolios in exchange for a flat fee (typically 0.20-0.50% of AUM annually). The OCIO model lets institutional clients access institutional-grade asset allocation expertise without building their own internal investment team. Key OCIO functions:Strategic asset allocation. The OCIO designs the asset-allocation framework (equity/bond/alternatives mix) based on client objectives, risk tolerance, and investment horizon.Implementation through manager selection. Rather than picking individual stocks, the OCIO selects managers (or ETFs) to fulfill each asset-class allocation. The implementation layer is often dominated by low-cost ETFs because they are cheap, diversified, and tax-efficient.Rebalancing and tactical positioning. The OCIO rebalances portfolios on a calendar or threshold basis and makes tactical positioning adjustments.Risk management and reporting. The OCIO monitors portfolio risk, manager performance, and provides regular reporting to the client.How to identify an OCIO 13F filerFour fingerprints distinguish OCIO 13Fs from active and passive equity managers:Fingerprint 1: 100% ETF allocationOCIO 13Fs typically hold 100% ETFs (or close to it) because ETFs are the most cost-efficient and tax-efficient implementation vehicle for asset-class exposure. Cambridge Associates' 13F has zero individual stocks. Russell Investments and Mercer OCIO file similarly. Active managers typically run 0-2% ETF exposure; passive index funds hold actual stocks rather than ETFs.Fingerprint 2: Vanguard or iShares dominanceOCIO ETF allocations are dominated by Vanguard ETFs (VOO, VT, VEA, VTI, VWO, VGIT, VTIP, VGLT, VGSH, etc.) or iShares ETFs (IVV, IEFA, IEMG, AGG, etc.). The choice reflects the providers' low expense ratios and broad index coverage. BlackRock OCIO typically uses more iShares; other OCIO providers split between Vanguard and iShares.Fingerprint 3: Multi-asset-class breadthOCIO 13Fs span US equity (large/mid/small cap), international equity (developed/emerging), fixed income (short/intermediate/long Treasuries, TIPS, corporate), commodities, and sometimes alternatives via ETF wrappers. The breadth signals strategic-asset-allocation implementation rather than equity-only stock-picking.Fingerprint 4: Position turnover is calendar-driven, not signal-drivenOCIO positions change quarter-over-quarter based on calendar rebalancing and tactical positioning, not on individual security-level signals. The position list is relatively stable; weight shifts reflect asset-allocation framework adjustments rather than stock-picking changes.The largest OCIO 13F filersProviderOCIO 13F SizeStyleCambridge Associates$6.31BEndowment-foundation focus, Vanguard ETF heavyRussell Investments~$30B+Multi-strategy OCIO, mixed Vanguard + iShares + proprietary fundsMercer Investment ManagementVariablePension and corporate OCIO focusAon Investments USAVariablePension and corporate OCIO focusBlackRock OCIOSubstantialiShares ETF dominantGoldman Sachs Asset Management OCIOVariableMixed implementation, some active-fund layerNorthern Trust Asset ManagementVariableBank-trust-affiliated OCIOHow to read OCIO 13Fs correctlyThree rules:Rule 1: Don't treat the ETF allocation as a trade signalOCIO ETF allocations reflect strategic-asset-allocation framework decisions, not stock-picking views. Cambridge's 26.24% in VOO does not mean Cambridge is bullish on US large-caps — it means the OCIO's strategic-allocation framework allocates ~26% to US large-cap exposure, and VOO is the cost-efficient implementation vehicle.Rule 2: Watch the allocation shifts as strategic-framework signalsIf Cambridge meaningfully shifts the equity-to-bond ratio quarter-over-quarter, the change signals broader OCIO industry view shifts on the equity/bond risk-reward balance. A 5%+ shift from equities to bonds across multiple OCIO 13Fs would be a notable institutional positioning signal.Rule 3: Compare across OCIO providers for consensus signalsWhen multiple OCIO providers shift toward (or away from) similar asset classes, the institutional consensus on strategic positioning is changing. Cross-checking Cambridge against Russell against Mercer can reveal whether allocation shifts reflect provider-specific or industry-wide thinking.What OCIO 13Fs are NOT useful forThree common misreads:Not stock-picking signals. The ETF allocation is implementation; the underlying ETF holdings are not OCIO discretionary picks.Not single-name conviction. No OCIO 13F holds individual stocks at meaningful weights. There is no 'OCIO conviction on NVDA' to extract.Not active-alpha signals. OCIO providers are not paid for alpha generation through stock selection. Their value-add is in asset-allocation framework design, manager selection, and risk management.What OCIO 13Fs ARE useful forTracking institutional strategic-asset-allocation positioning. Aggregating across major OCIO providers reveals how institutional client portfolios are currently positioned across equity, fixed income, international, and alternatives.Identifying ETF flows by mandate. When Cambridge shifts toward VEA (international developed-markets), the OCIO industry is rotating toward international equity at the institutional client level.Cross-checking against direct-asset-manager positioning. OCIO allocation shifts often precede direct-asset-manager positioning shifts because OCIO clients are increasingly the marginal allocator at the institutional level.For real-time tracking of OCIO and other institutional asset-allocation filings, see the institutional signals feed. For related reading techniques on non-stock-picker 13F filings, see our multi-family office decoder and the broader explainer hub. ## FAQ ### What is an OCIO? An OCIO (outsourced-CIO) is a discretionary investment-management service where an institutional consulting firm takes direct authority over a client portfolio in exchange for a flat fee (typically 0.20-0.50% of AUM annually). OCIO providers include Cambridge Associates, Russell Investments, Mercer, Aon, BlackRock OCIO, Goldman Sachs Asset Management OCIO, and Northern Trust Asset Management. The industry manages approximately $2.5 trillion globally. ### Why is Cambridge Associates' 13F entirely in ETFs? Cambridge's OCIO business implements strategic asset allocation through low-cost ETF building blocks rather than individual stock-picking. The $6.31 billion 13F holds 100% ETFs because ETFs provide cost efficiency (0.03-0.10% expense ratios), instant diversification, tax efficiency, and align with Cambridge's value-add (asset allocation framework, manager selection, risk management). The firm does not provide stock-picking research. ### How do I identify an OCIO 13F filer? Four fingerprints: (1) 100% ETF allocation with zero individual stocks; (2) Vanguard or iShares dominance in the ETF mix; (3) multi-asset-class breadth covering US equity, international, fixed income, commodities, alternatives via ETF wrappers; (4) position turnover that is calendar-driven rather than signal-driven. Cambridge Associates is the cleanest example; Russell, Mercer, Aon, BlackRock OCIO file similarly. ### Should I follow OCIO ETF allocation as a trade signal? No. OCIO ETF allocations reflect strategic-asset-allocation framework decisions, not stock-picking views. Cambridge's 26.24% in Vanguard S&P 500 ETF does not mean Cambridge is bullish on US large-caps — it means the OCIO's strategic-allocation framework allocates ~26% to US large-cap exposure, and VOO is the cost-efficient implementation vehicle. The allocation is implementation, not investment view. ### What is OCIO 13F data useful for? Three practical uses: (1) tracking institutional strategic-asset-allocation positioning across endowments, foundations, and pension funds; (2) identifying ETF flows by mandate type (shifts toward VEA signal international equity rotation); (3) cross-checking against direct-asset-manager positioning, since OCIO clients are increasingly the marginal allocator at the institutional level. Allocation shifts often precede broader institutional repositioning. ### Why has the OCIO industry grown? Three structural drivers: (1) institutional clients (endowments, foundations, pension funds, family offices) face increasing complexity in asset allocation and want institutional-grade expertise without building internal investment teams; (2) the OCIO fee structure (0.20-0.50% of AUM) is competitive versus building a full internal team; (3) the rise of low-cost ETFs has made strategic-allocation implementation more cost-effective, supporting OCIO economics versus active manager fees. --- Source: 13F Insight — https://13finsight.com/learn/ocio-13f-cambridge-russell-mercer-aon-reading-guide Author: Sarah Mitchell — https://13finsight.com/authors/sarah-mitchell Last updated: 2026-05-15T05:59:15.330Z