A $3,950 paycheque on May 1st.
Overdrawn by May 31st.
Ryan D'Souza is a 24-year-old data analyst in Toronto, nine months into his first job. He wants a $3,000 emergency fund but keeps ending the month at zero. This shows where he is wasting money, the opportunity cost of that spending, and his plan to reach $3,000.
…
How $3,950 becomes an overdraft
The month begins with a small balance and a full paycheque, and ends below zero. Each downward step is a group of spending. Amber marks the groups with the most waste.
Three tiers, not one number
Waste is not the same as spending. This separates money that bought nothing from money Ryan cannot see, and both of those from lifestyle he chose. Every figure opens to the transactions behind it.
Where the money went
Every dollar of spending, grouped. Amber marks the categories with the most waste.
Most of the spending happens early in the month
Darker cells are heavier spending days. Most of the spending happens in the first half of the month, and the balance falls steadily until the overdraft on May 31.
AI, cross-checked by rules
Claude, a frontier model from Anthropic, categorized every transaction. A separate rules engine did the same, independently. The score below is the model against a hand-labelled ground truth. The table is where the two methods disagreed, which is where a person should look.
…
… transactions. The model was right on …, the rule was right on …. Neither is trustworthy on its own.
This is the whole reason for the cross-check. A single wrong category can flip Ryan's decision about what to cut, and frontier models do make errors on financial data.5
| Transaction | AI said | Rules said | Truth | Right |
|---|
Low-confidence calls the model would not make on its own.
Ryan's path to $3,000
Choose what Ryan changes and the timeline updates. The first three are the no-sacrifice cuts. The last two are his call.
Put in a 3% account, the same amount would be … after one year, of which … is interest Ryan gives up by spending it instead.
What I would tell Ryan
Plain steps, ordered by effort. The first four take an afternoon and cost nothing to do.
Cancel five unused subscriptions this week
LinkedIn Premium, Disney+, Amazon Prime, the Netflix add-on, and Crave.2 He named Netflix and Spotify as the only two he uses, so the other five are unused. Crave was also billed twice this month, so cancelling it stops the fee and the duplicate is a separate one-time refund.
Set a low-balance alert
The overdraft fee happened because he did not see zero coming. A free TD alert defaulting to a $100 balance removes it.7
Move the first $250 on payday, before spending
Automate a transfer the day salary lands, ideally into a TFSA so the interest is tax-free.8, 9 He never sees it, so he cannot spend it.
Use TD machines and track the cash
Three withdrawals were at non-TD machines that add a surcharge.4 The bigger issue is that $560 in cash left with no record. A weekly cash cap makes it visible.
Decide on the gym
At one or two visits a month he is paying $30 to $60 a visit.3 Commit to using it, or switch to a pay-per-visit pass.
Steps 1, 2, and 4 alone recover about $417 a month with nothing Ryan enjoys removed, which reaches $3,000 in roughly seven months. A starter fund of this size is a sound first goal,10 and Ryan is not alone in struggling to save: the Canadian household saving rate was 4.4% late in 2025.11
The pipeline
The statement runs through two independent analyses and an evaluation, then into a static page that makes no live model call.
References and sources 11 sources
- Ryan D'Souza's May 2026 TD chequing statement, the dataset analysed here (provided for the challenge).
- C+R Research, "Subscription Service Statistics and Costs" (consumers underestimate subscription spending by about $133 a month, and 42% have forgotten a paid subscription while still being charged). crresearch.com
- DellaVigna, S., and Malmendier, U. (2006). "Paying Not to Go to the Gym." American Economic Review 96(3): 694-719. aeaweb.org
- TD Canada Trust, "List of Services and Fees," effective March 5, 2026 (non-TD ATM withdrawal $2.00). td.com
- "Deficiency of Large Language Models in Finance: An Empirical Examination of Hallucination" (arXiv 2311.15548). arxiv.org
- Bank of Canada policy rate held at 2.25% (June 2026), and Ratehub high-interest savings rates of about 2 to 3%. bankofcanada.ca, ratehub.ca
- TD Canada Trust, "TD Alerts" (free threshold alerts, default at a $100 balance). td.com
- Thaler, R., and Benartzi, S. (2004). "Save More Tomorrow." Journal of Political Economy 112(S1): S164-S187. journals.uchicago.edu
- Canada Revenue Agency, TFSA contribution limits (2026 limit $7,000). canada.ca
- Financial Consumer Agency of Canada, "Setting up an emergency fund." canada.ca
- Statistics Canada, "Distributions of household economic accounts, Q4 2025" (household saving rate 4.4%). statcan.gc.ca
The full source notes, including the design and AI-method sources, are in SOURCES.md in the repository.