Sunk Cost Fallacy: How to Avoid Costly Financial Mistakes in 2025

Ever stayed too long at a bad movie because you already paid for the ticket? Or held onto a losing investment, convinced things would turn around simply because you’d already poured so much in? Welcome to the sunk cost fallacy—a psychological pitfall that’s quietly draining the wallets of Australians across the country.

What is Sunk Cost, and Why Does It Matter in 2025?

A sunk cost is money, time, or effort you’ve already spent and can’t recover. The rational thing to do is ignore those past investments when making future decisions. But in reality, our brains rebel: we feel compelled to ‘get our money’s worth’, often leading to even bigger losses.

With inflation biting and cost-of-living pressures still high in 2025, the ability to walk away from bad investments—whether in shares, property, subscriptions, or everyday purchases—has never been more important for Australian households.

• Example: In 2024, over 40% of Australians reported sticking with underperforming investments, citing the money they’d already put in as the main reason. (Source: ASX Investor Study 2024)

• Policy update: ASIC’s 2025 investor guidance explicitly warns about the dangers of the sunk cost fallacy, urging consumers to focus on future value rather than past losses.

Everyday Sunk Cost Traps for Australians

The sunk cost fallacy isn’t just for the stock market. It creeps into our daily lives, affecting everything from gym memberships to business decisions.

• Unused Subscriptions: Australians waste an average of $1,200 per year on unused streaming, fitness, and app subscriptions. Many continue paying simply because they’ve ‘already paid so much’.

• Renovation Regrets: Homeowners often throw good money after bad during renovations, refusing to halt a project that’s over budget or poorly planned because they’ve already invested heavily in it.

• Small Business Decisions: In the SME sector, business owners frequently persist with unprofitable products or marketing campaigns, rationalising the decision based on previous outlays rather than future prospects.

Breaking the Cycle: How to Outsmart the Sunk Cost Fallacy

Escaping the sunk cost trap requires a shift in mindset—and a willingness to make tough calls.

• Focus on Future Gains, Not Past Losses: Always ask: “If I hadn’t spent this money already, would I invest more today?” If the answer is no, it’s time to cut your losses.

• Set Clear Exit Rules: For investments, set predefined ‘stop-loss’ levels. For subscriptions or business projects, review regularly and cancel if value isn’t clear.

• Seek a Second Opinion: When emotions cloud your judgement, get input from a financially savvy friend or colleague who isn’t emotionally invested.

• Leverage Technology: Use budgeting apps to flag recurring charges and underused subscriptions, making it easier to spot where you’re falling for the sunk cost fallacy.

In 2025, many financial apps and platforms in Australia now incorporate ‘decision nudges’—alerts that prompt users to reconsider ongoing costs and remind them that past spend shouldn’t dictate future choices.

Real-World Turnarounds: Australians Who Beat the Sunk Cost Trap

Meet Lisa, a Sydney-based investor who poured $15,000 into a tech startup during the 2022 boom. By 2024, the company was struggling, but Lisa hung on, convinced the tide would turn. After attending a 2025 ASIC webinar on behavioural biases, she finally sold her stake and reinvested in a diversified ETF—recouping her losses within a year.

Or consider James, a Melbourne small business owner who continued running a loss-making product line out of loyalty to his team and the money he’d spent on equipment. A frank review of his financials in early 2025 helped him cut the line, freeing up cash to expand into a more profitable market segment.

Conclusion: Make 2025 the Year You Walk Away from Bad Bets

Australians are under more financial pressure than ever, and letting sunk costs dictate your decisions can quietly erode your wealth. By recognising the trap, resetting your approach, and harnessing the latest tools and policy guidance, you can make smarter, more confident money moves this year.