Investopoly Ep 395: Financial modelling for wealth: advice or sales pitch?
Feb 10, 2026
They unpack how financial models can be shaped to sell outcomes rather than reveal truth. The conversation flags optimistic assumptions, understated costs, and the dangers of straight-line returns. It highlights sequence risk, overstated rental cash flow, and execution and refinancing pitfalls. The focus is on stress-testing, conservative inputs, and comparing models across asset classes.
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Models Reflect Assumptions, Not Fate
- Financial models reflect assumptions, not certainties, and can be shaped to produce any result.
- Stuart Wemyss warns that when model builders profit from transactions, assumptions often skew optimistic.
Commissions Once Dressed Sales As Advice
- Before commissions were banned in 2013, financial advice often disguised product sales and damaged client trust.
- Stuart Wemyss cites the post-2013 rise of ETFs as an outcome of removing commissions from advice.
Use Conservative, Evidence-Based Assumptions
- Use conservative, evidence-based assumptions and justify them with historical data when modelling returns and rates.
- Stress-test key inputs like interest rates by modeling higher scenarios and explain the evidence behind chosen benchmarks.
