When submissions to the government’s request for expressions of interest (REOI) for the Advanced Capability Investment (ACI) fund close this afternoon, officials will face a familiar challenge: not a shortage of proposals, but uncertainty about what Australia’s growing innovation investment system is trying to achieve.

The fund itself is a welcome step, with the federal government expected to contribute up to A$500 million alongside private capital to support strategically important technologies. The instinct to crowd in private investment and share risk is sound.

But the REOI addendums capture the real mood in the room: sophisticated bidders asking basic questions about structure, instruments, governance and how this interacts with procurement; and Defence keeping key parameters deliberately flexible. That flexibility may be necessary to attract credible capital partners. But it also heightens the risk of a vehicle with blurry objectives and difficult-to-measure outcomes.

Australia already operates several public investment instruments. The Future Fund acts as the nation’s sovereign wealth fund. The National Reconstruction Fund aims to reshape domestic industry. The Future Made in Australia agenda carries large policy commitments, alongside grant programs administered by agencies such as the Australian Renewable Energy Agency. Each tool targets a different slice of the economy. Yet for founders, investors and industry partners, the broader system is increasingly difficult to interpret and navigate.

Multiple instruments are not the problem. Mature innovation ecosystems rely on layered financing sources. The issue in Australia is that the mission connecting these instruments is often poorly distilled and articulated. Across several policy domains, programs appear faster than the explanation of how they fit into a coherent national economic strategy.

That matters because the ACI fund is being positioned as a bridge: between early technology development and operational deployment; between private capital and national interest; and between dual-use and Defence-relevant technology. Bridges only work when both ends are stable.

If the fund is to succeed, the government needs to first answer some basic questions: what role is it meant to play within the broader ecosystem? Is it primarily an economic instrument designed to grow emerging technology sectors? Is it a national security tool aimed at accelerating defence-relevant capability, or a venture vehicle expected to generate strong commercial returns alongside strategic benefit?

The REOI responses indicate Defence is trying to satisfy all three audiences. It wants a commercial, investable vehicle that can crowd in private capital. It also wants patient capital that can help companies mature technologies, scale and commercialise. And it wants that effort aligned to priority capability areas.

Each model suggests different design choices.

If financial return becomes the dominant metric, the fund will naturally gravitate toward clearer exit paths and de-risked opportunities. That might generate respectable returns but under-serve the harder sovereign problems where security constraints, long timelines or specialised demand slow commercial scale.

If the fund is instead treated as a de facto defence accelerator, it risks duplicating existing innovation pathways and confusing the boundary between investment and procurement. The addendums emphasise that investment does not create any expectation of or commitment to procurement. Procurement needs to run separately under federal rules. That is the correct probity posture, but it also exposes the central tension. You cannot claim ‘demand signal’ as the primary value proposition while building a structure that cannot credibly connect to demand.

Neither outcome would justify creating a new instrument.

There is a third option that fits both the addendums and Australia’s ecosystem realities: treat the ACI fund explicitly as a fund-of-funds platform, potentially with multiple streams of funding for different stages and investment types.

A fund-of-funds approach would allow the federal government to serve as an anchor investor across specialist managers. This would spread risk, leverage existing diligence and portfolio support capability, and avoid the market distortion that can come from concentrating a very large pool of public capital in a single, centrally managed vehicle. It would also create space for new entrants dedicated to defence and dual-use sectors without forcing Defence to build an in-house investing machine.

Crucially, it keeps government focused on shaping markets rather than picking stock. It also aligns with the governance reality the addendums imply: Defence understands the conflict risks inherent in being both investor and potential customer, and it is seeking structures that preserve probity while still achieving national interest objectives.

But capital architecture alone won’t solve the deeper problem.

Even a perfectly designed fund-of-funds requires a clear mission and a credible transition pathway. If the goal is sovereign capability, investment must be linked to demand signals, test and evaluation pathways, and acquisition on-ramps that can absorb successful technologies. Without that, the fund becomes a pool of money looking for plausible deals, rather than a capability mechanism designed backwards from Defence outcomes.

This is where the opportunity cost becomes unavoidable.

If the fund cannot demonstrably strengthen the pathway from investment to operational capability – if it cannot increase the probability that priority technologies get fielded, not just funded – then why use a venture instrument at all? A poorly structured investment vehicle risks delivering less strategic value than simply allocating the same capital to direct capability acquisition.

The ACI fund will ultimately be judged not by the volume of capital it deploys, but by whether it strengthens the connection between investment and capability.

If it does, it could become a useful bridge between Australia’s capital markets and its strategic technology priorities.

If it does not, the uncomfortable conclusion will be that half a billion dollars may have been better spent buying capability directly. If ACI cannot measurably increase the rate at which priority technologies transition into fielded capability, Defence should spend the A$500 million on acquisition instead.