Treasury Stock Method Explained for Australian Investors (2025 Guide)

For Australian investors, understanding how companies report their earnings is crucial. One metric often in the spotlight is diluted earnings per share (EPS), and the Treasury Stock Method (TSM) plays a starring role in calculating it. With the 2025 financial reporting season bringing renewed focus on corporate transparency and updated accounting standards, it’s time to demystify how the TSM works and why it matters for your portfolio decisions.

What is the Treasury Stock Method?

The Treasury Stock Method is an accounting technique used to calculate the potential dilution of earnings per share (EPS) that could occur if all in-the-money options and similar convertible instruments were exercised. In plain English: it estimates how many new shares could hit the market if employees or investors convert their options, and how that would impact the company’s reported profitability per share.

• Options and Warrants: These are financial instruments giving holders the right to buy company shares at a predetermined price.

• In-the-money: When the exercise price is below the current market price, making conversion attractive.

• Diluted EPS: A more conservative measure of company profitability, factoring in all potential shares from options and convertibles.

The TSM assumes that all in-the-money options are exercised at the beginning of the reporting period. The company then uses the proceeds from these exercises to buy back as many shares as possible at the average market price, hence the name “treasury stock.” The net increase in shares is added to the denominator in the diluted EPS calculation.

Why the Treasury Stock Method Matters in 2025

With the Australian Securities & Investments Commission (ASIC) placing a sharper lens on earnings quality in 2025, companies are under pressure to present more transparent and accurate EPS figures. The TSM ensures that investors get a realistic picture of potential dilution, especially as equity compensation plans have grown in popularity among ASX-listed firms.

Example: Consider a tech company listed on the ASX with 10 million shares outstanding and 1 million in-the-money options at an exercise price of $5. If the average share price in 2025 is $10, and all options are exercised:

• Proceeds from exercise: 1,000,000 x $5 = $5,000,000

• Shares bought back at market price: $5,000,000 / $10 = 500,000 shares

• Net new shares added: 1,000,000 (issued) - 500,000 (repurchased) = 500,000

This means the diluted share count rises to 10.5 million, lowering the reported EPS — a key consideration for both current and prospective investors.

In 2025, the Australian Accounting Standards Board (AASB) has reaffirmed alignment with IFRS guidelines, ensuring that the TSM remains the standard approach for diluted EPS calculations in Australia. This uniformity aids in cross-market comparisons and reduces the risk of ‘creative’ earnings presentations.

What Should Investors Watch For?

When reviewing company reports or analyst notes in 2025, keep an eye out for:

• Large Option Grants: Tech and growth companies, in particular, may have significant potential dilution on the horizon.

• Disclosure Quality: Top-tier companies will clearly explain their diluted EPS calculations and the impact of the TSM.

• Regulatory Updates: ASIC has flagged closer scrutiny of share-based payment disclosures and diluted EPS presentations in its 2025 regulatory agenda.

It’s also worth noting that some companies may have complex capital structures, including convertible bonds or preference shares. While the TSM specifically addresses options and similar instruments, broader diluted EPS calculations may require other methods for these additional securities.

TSM in Action: 2025 Real-World Example

Let’s say Afterpay (now part of Block, Inc.) reports its 2025 results and shows robust growth — but also a spike in share-based compensation for staff. Analysts and investors should use the TSM-adjusted diluted EPS to assess true profitability. In a year where share prices have rebounded, more options are likely to be in the money, increasing the importance of accurate TSM application. This scenario is playing out across the ASX, especially in tech, mining, and biotech sectors where equity incentives are common.

Conclusion: Why TSM Belongs in Every Investor’s Toolkit

The Treasury Stock Method is more than just an accounting quirk — it’s a vital lens for assessing the real value of a company’s earnings. As 2025 brings new regulatory focus and evolving market dynamics, understanding how TSM shapes diluted EPS will help Australian investors make smarter, more confident decisions.