Semi-transparent active ETFs are actively managed exchange-traded funds that do not publish their full portfolios every day. Instead, they disclose their actual holdings quarterly, with a delay of up to 60 days, and give the market a stand-in basket to use for pricing and trading in the meantime. The structure exists to let a portfolio manager pick stocks without competitors and traders watching every move, while preserving most of the tax efficiency and intraday tradability that make ETFs attractive. As of late 2024, active ETFs held about 9% of all ETF assets, but most of that money now sits in fully transparent active funds rather than semi-transparent ones.
How the Hidden Portfolio Actually Trades
Standard ETFs operate under SEC Rule 6c-11, which requires daily disclosure of every holding. That transparency powers the arbitrage that keeps an ETF’s market price close to the value of its underlying assets. Semi-transparent funds cannot meet the daily disclosure condition, so each one operates under an individual exemptive order granted by the SEC under the Investment Company Act of 1940.1Federal Register. Federal Register 90 FR 17853 – Self-Regulatory Organizations; Cboe BZX Exchange, Inc. The order spells out how the fund will replace daily disclosure with other tools that still let market makers price shares fairly.
The Proxy Portfolio
Since market makers cannot see the real holdings each day, they work from a proxy portfolio: a published basket of securities designed to track the performance and risk profile of the actual holdings without revealing them. The proxy contains many of the same securities as the real portfolio, but weightings and some specific positions are altered to protect the manager’s strategy.
Authorized participants use this basket to create and redeem ETF shares. They deliver the securities in the proxy to the fund sponsor and receive new shares in return, or vice versa on redemption. The whole system works only if the proxy correlates tightly with the actual holdings. Fund sponsors monitor that correlation daily and adjust the proxy as needed. If it drifts, market makers lose confidence in their pricing and bid-ask spreads widen.
The Verified Intraday Indicative Value
Alongside the proxy, the fund publishes a Verified Intraday Indicative Value, known as the VIIV. It is calculated from the actual holdings and updated every second during the trading day by the listing exchange or market data vendors.2Federal Register. Self-Regulatory Organizations; Cboe BZX Exchange, Inc.; Notice of Filing of Amendment No. 2 Two independent calculation engines produce the number simultaneously, and a pricing verification agent compares them continuously to catch errors. On most brokerage platforms, the VIIV shows up alongside the market price so you have a real-time reference when placing orders.
The system has hard limits. The exchange halts trading if the two calculation engines diverge by more than 25 basis points for 60 straight seconds, if securities representing 10% or more of the portfolio stop trading, or if the VIIV simply stops being disseminated at one-second intervals.2Federal Register. Self-Regulatory Organizations; Cboe BZX Exchange, Inc.; Notice of Filing of Amendment No. 2 These circuit breakers protect you from trading blind, but they also mean semi-transparent ETFs are more prone to trading halts than standard ETFs during volatile sessions.
A Variant Without a Published Proxy
Not every semi-transparent ETF uses a proxy basket. Under the Precidian ActiveShares structure, the fund shares its actual portfolio confidentially with an authorized participant representative, a capital markets intermediary who handles creation and redemption transactions for the authorized participants. That intermediary sees the real holdings; confidentiality agreements keep the information from reaching the broader market. Strategy protection is stronger because no proxy gets published, but pricing and liquidity depend entirely on the intermediary.
What These Funds Can Hold
Exemptive orders limit semi-transparent active ETFs to long-only positions in liquid, U.S.-exchange-listed equity securities. That means domestic stocks, cash, and other U.S.-listed exchange-traded products. The restriction exists because the pricing agent has to value the whole portfolio in real time during U.S. market hours, and assets that trade on foreign exchanges in different time zones make that impossible. Illiquid securities, complex debt, and most derivatives are generally off the table because their values are hard to mirror in a proxy.
The SEC has begun granting amended orders that allow certain funds to add fixed income and foreign holdings, but with a condition: those positions must sit in a fully transparent sleeve disclosed daily under standard ETF rules, while the U.S. equity positions stay in the semi-transparent sleeve.3U.S. Securities and Exchange Commission. Investment Company Act Release No. 35486 The ratio between the two sleeves in the published tracking basket must match the ratio of each investment type in the actual fund.
What You Can See, and When
Semi-transparent active ETFs disclose their real holdings quarterly, typically with a lag of up to 60 days after the quarter ends.1Federal Register. Federal Register 90 FR 17853 – Self-Regulatory Organizations; Cboe BZX Exchange, Inc. The delay is deliberate. Publishing trades immediately would let outside traders buy ahead of the manager’s positions and drive up prices before the fund could finish accumulating them.
Every prospectus has to state clearly that the fund is semi-transparent and explain how that feature affects trading costs. The SEC has issued guidance on website posting requirements pushing funds to make this information easy to find before you invest.4U.S. Securities and Exchange Commission. ADI 2025-15 – Website Posting Requirements Between quarterly filings, what you get is the strategy description, the daily proxy basket, and the per-second VIIV. What you do not get is the exact list of what you own on any given day.
Costs and Taxes
You buy and sell shares through a brokerage account the same way you would trade a stock. Online commissions at most major brokerages have effectively dropped to zero for ETF trades.5Fidelity Investments. Commissions, Margin Rates, and Fees6Vanguard. Brokerage Services Commission and Fee Schedules
The bid-ask spread is the cost that actually matters. Because market makers face more uncertainty pricing a fund they cannot fully see, spreads on semi-transparent ETFs tend to run wider than on comparable transparent funds. In calm markets, the difference may be small. In volatile ones, when the VIIV becomes less reliable and hedging gets harder, spreads can widen substantially, and the SEC has noted that market makers may simply stop quoting rather than risk losses.7U.S. Securities and Exchange Commission. Exchange-Traded Funds (Final Rule) Use limit orders.
On top of the spread, you pay an expense ratio for active management. Active ETFs broadly averaged 25 to 37 basis points as of 2024, though individual funds vary. Passive index ETFs often charge under 10 basis points, so the active premium is real.
The tax picture is where the ETF wrapper earns its keep. Actively managed mutual funds often sell securities to meet redemptions, generating capital gains that get passed on to every remaining shareholder. ETFs mostly avoid this because shares trade between investors on the exchange, and when large blocks do get redeemed, the fund transfers securities in kind to the authorized participant rather than selling them. The fund sponsor can hand over the tax lots with the lowest cost basis first, pushing the most tax-inefficient positions out and raising the average cost basis of what remains. Many ETFs, including semi-transparent active ones, distribute little to no capital gains in a typical year. The catch: in-kind transfers work best with liquid U.S. equities. Assets that must be sold to be moved lose some of that advantage, which is another reason the eligibility rules stay tight.
Risks Specific to the Structure
Reduced daily transparency creates a set of risks that do not exist with standard ETFs:
- Wider bid-ask spreads. Market makers price uncertainty into their quotes, and less information means higher costs every time you buy or sell.
- Premium and discount risk. When the arbitrage mechanism works less efficiently, the market price can drift from net asset value. During market stress, that means buying at a premium or selling at a discount.7U.S. Securities and Exchange Commission. Exchange-Traded Funds (Final Rule)
- Proxy tracking error. If the proxy basket diverges from the real portfolio, the pricing tools market makers rely on become less accurate, and the market price may not reflect the fund’s actual performance in real time.
- Trading halts. VIIV circuit breakers can pull the fund out of trading at bad moments. You cannot exit a position during a halt.
- Limited visibility into holdings. You know the strategy and see the proxy, but you will not know exactly what you own until the quarterly disclosure arrives weeks later. If the manager makes a concentrated bet that goes wrong, you may not learn about it until the damage shows up in the share price.
These are trade-offs, not disqualifiers. You are paying for active management with less ability to verify what that management is doing on any given day.
Why Most Active ETFs Now Skip the Semi-Transparent Route
Semi-transparent active ETFs launched with real momentum starting in 2020, and several major asset managers adopted the structure. The market has since moved decisively toward fully transparent active ETFs, which publish complete holdings daily just like index ETFs. The share of new ETF launches that were actively managed grew from roughly 20% in 2020 to about 45% by 2024, and most of those chose full transparency.
Full disclosure makes life easier for market makers, which tightens spreads and reduces premium-discount risk for investors. Several fund families that started semi-transparent have converted their products to fully transparent structures, concluding that the wider spreads and added complexity were not worth the strategy protection. The feared wave of front-running against daily-disclosed active strategies has largely not materialized, at least not enough to outweigh the liquidity benefits.
Semi-transparent active ETFs still have a place for managers running highly concentrated or capacity-constrained strategies, where even a few days of front-running could erode returns meaningfully. For most active equity strategies, the industry has tilted toward showing the cards and letting tighter spreads do the rest. If you are considering a semi-transparent fund, that context is worth carrying with you: check whether a fully transparent version of a similar strategy exists, and compare spreads and expense ratios before committing.