Fact-check

Post proposing gain-side indexation instead of cost-base indexation for founder exits

This submission is strongest on one narrow arithmetic criticism of the Budget's CGT redesign: if a founder really has a zero cost base, cost-base indexation does not create any uplift. The worked hypothetical that a $1 million gain reduced by a 25 per cent inflation factor becomes $750,000 is also mathematically correct as an alternative design example. But the stronger claims that founders and small business owners are now categorically overtaxed relative to investors, that gain-side indexation is a clean universal fix needing no carve-out, or that the reform will slow productive capital deployment all require additional policy assumptions that the post does not resolve.

2 supported 3 requires assumptions

Back to dashboard Model the zero-cost-base founder case

Prefills a post-2027 founder-style exit with little or no cost base so the submission's asymmetry critique can be checked against explicit concession and rate assumptions.

Submitted text

There is such an easy solution to Labor's CGT problem that now overtaxes founders and small business owners relative to investors. Switch indexing to the profit rather than the cost. If a founder launches a company and sells 10 years later for $1m, their cost base for those shares is probably zero. Indexing means multiplying the price they paid by inflation to make it higher. That works for investors, but it still leaves the cost base at zero for founders because $0 x anything is still zero. However, if the $1m exit was reduced by an inflation indexing factor, that would result in a lower gain. Imagine the inflation was 25% over that period. Instead of the cost base rising by 25%, the gain goes down by 25%, to $750k. That's 25% less tax for the founder. Tax on $750k of gain instead of $1m. There are a few issues, mostly that it will collect less tax ... Overall, it's a clean mathematical solution that could be applied universally to all cost bases so no carve out is required. Startup founders might not go overseas, and cafe and retail founders might still take the risk ... it doesn't change the fact that this CGT change is unfair and punitive, and will slow the deployment of capital to productive enterprise.

Per-claim verification

requires assumptions 83% confidence

The Budget 2026 CGT redesign now overtaxes founders and small business owners relative to investors as a class.

“Labor's CGT problem now overtaxes founders and small business owners relative to investors.”

The post identifies a real asymmetry for some low-cost-base founder cases, especially when compared with investors whose cost base can be meaningfully indexed. But the broader relative-tax claim is still too categorical as stated. It depends on what kind of investor is being used as the comparator, whether the investor is in a new build that keeps a special CGT choice, whether the founder or small business owner can use Subdivision 152 concessions, and what marginal tax rate and holding pattern are assumed.

Assumptions required

Assumes the founder or owner does not materially benefit from the small business CGT concessions.
Assumes the comparator investor has a cost base and holding pattern that produces a materially better outcome under indexation.
Assumes a like-for-like comparison across taxpayer type, marginal rate, and asset structure.

Alternative defensible framings

Some zero-cost-base founder cases look harsher under cost-base indexation than investor cases with a meaningful indexed cost base.
Whether founders are categorically overtaxed relative to investors depends on concessions, asset mix, and the comparator chosen.

Primary sources

Budget 2026-27 Tax reform page Capital gains tax · p.1 The Government will replace the 50 per cent Capital Gains Tax discount with a discount based on inflation and introduce a minimum 30 per cent tax on gains from 1 July 2027. ATO: Small business CGT concessions eligibility overview How the concessions work · p.1 The small business CGT concessions allow you to reduce, disregard or defer some or all of a capital gain from an active asset used in a small business.

supported 97% confidence

If the relevant founder share cost base is zero, cost-base indexation still leaves the indexed cost base at zero.

“$0 x anything is still zero.”

That arithmetic point is correct. If the starting cost base is genuinely zero, multiplying it by an inflation factor does not create a positive indexed cost base. That is the narrow mathematical weakness the post is highlighting in a founder case with little or no acquisition cost.

Alternative defensible framings

The zero-cost-base problem is really a problem for founder cases where the first-element cost base is nil or very low.

Primary sources

ATO: Cost base of assets Work out the cost base for a capital gain · p.1 The cost base of a capital gains tax asset is generally what it cost you to buy it, plus other costs you incur to hold and dispose of it. Budget 2026-27 Tax reform page Capital gains tax · p.1 The Government will replace the 50 per cent Capital Gains Tax discount with a discount based on inflation.

supported 98% confidence

Under the post's proposed alternative design, a $1 million gain reduced by a 25 per cent inflation factor would become a $750,000 taxable gain.

“Imagine the inflation was 25% over that period. Instead of the cost base rising by 25%, the gain goes down by 25%, to $750k.”

As a worked arithmetic example of the author's proposed alternative design, this is correct: reducing a $1 million nominal gain by 25 per cent produces a $750,000 gain. That also means the tax base in the example falls by 25 per cent relative to a $1 million taxable gain. The check here is only the arithmetic of the hypothetical, not whether the law uses that design.

Alternative defensible framings

The worked example is mathematically sound as an illustration of a gain-side indexation design.

Primary sources

Budget 2026-27 Tax reform page Capital gains tax · p.1 The Budget chooses cost-base indexation and a minimum 30 per cent tax on gains, which is why the post is offering a different mathematical design.

requires assumptions 85% confidence

Gain-side indexation is a clean universal CGT fix that could replace founder carve-outs.

“It's a clean mathematical solution that could be applied universally to all cost bases so no carve out is required.”

This is a design judgement, not a settled fact. The proposal would address one narrow asymmetry in zero-cost-base founder cases, but it does not by itself resolve the rest of the policy architecture. Lawmakers would still need to decide how the 30 per cent minimum tax interacts with the proposal, how to treat losses and apportionment, how existing small business concessions should interact with it, and whether broad investor distributional goals are still being met. Calling it a universal no-carve-out solution therefore overstates how much work the arithmetic alone does.

Assumptions required

Assumes lawmakers would want to replace cost-base indexation with gain-side indexation across all asset classes.
Assumes the proposal integrates cleanly with the 30 per cent minimum tax and other CGT concessions.
Assumes solving the zero-cost-base founder asymmetry is the main policy problem that needs fixing.

Alternative defensible framings

Gain-side indexation is one plausible way to reduce the zero-cost-base founder asymmetry without drafting a founder-only concession.
Whether it is the cleanest universal solution is a policy-design question, not a mathematical certainty.

Primary sources

Budget 2026-27 Tax reform page Capital gains tax · p.1 The reform combines inflation indexation with a minimum 30 per cent tax on gains from 1 July 2027. ATO: Small business CGT concessions eligibility overview How the concessions work · p.1 The small business CGT concessions already reduce, disregard or defer some gains, which shows the existing design still contains carve-out-style relief choices.

requires assumptions 77% confidence

The Budget 2026 CGT redesign will slow the deployment of capital to productive businesses.

“This CGT change is unfair and punitive, and will slow the deployment of capital to productive enterprise.”

This is a plausible concern, but it remains a forward-looking behavioural claim rather than something established by the current primary-source set. The Budget clearly changes after-tax founder and investor incentives, yet the same package also claims to support innovation through venture-capital and startup measures. Whether productive capital deployment slows on net depends on behavioural responses, concession use, and how investors trade off the tax increase against those offsets.

Assumptions required

Assumes the CGT redesign outweighs the Budget's other startup and venture-capital support measures.
Assumes capital allocators are materially sensitive to this specific after-tax change at the margin.
Assumes founder and investor behaviour does not adjust through other structures or concessions.

Alternative defensible framings

The redesign may weaken some founder and productive-capital incentives, but the net investment effect is still contested.
The source base establishes a tax change, not a mechanically proven collapse in productive capital deployment.

Primary sources

Budget 2026-27 Tax reform page Capital gains tax · p.1 The reform changes how post-1 July 2027 gains are taxed, which is why concerns about capital allocation arise in the first place. Budget 2026-27 Productivity page Startup and venture measures · p.1 The Budget also presents itself as supporting innovation and investment through venture-capital and productivity measures.