The daily NAV close — run it, break it, watch it defend investors.
Every evening a lean fund turns a spreadsheet into a number people wire money against. This is that close, live: a (fictional) Singapore boutique's eight-name book — priced off Yahoo / Google Finance, reconciled to a broker statement, with today's trade blotter — and the six integrity gates that stand between the sheet and the investors. The yellow cells are genuinely editable: break anything, or load one of the five classic failures, and watch which gate catches it, what it would have cost, and who it would have short-changed.
Honest-AI note. The close, the gates and every number run live in your browser — deterministic code, recomputed on each keystroke. The AI layer, labelled where it appears: the exception memo the fund manager receives when a close is held (what happened, impact, likely cause, action) — drafted by Claude at build time here, per-incident in production.
| Ticker | Name | CCY | Book qty ✎ | Broker qty ✎ | Mark ✎ | Prior | Value (S$) | Tie |
|---|
| Time | Ticker | Side | Qty | Price | Value | In the book? | Broker | Match |
|---|
01The gate is the product
Automation that produces a number is easy; automation that refuses to send a wrong one is the discipline. Every downstream demo in this series — the read-only AI, the watchdogs, the month-end pack — exists to protect this one moment: release.
02The scariest failure looks perfectly normal
The unbooked trade leaves NAV exactly right — missing shares and un-spent cash cancel. Only reconciling positions and the blotter to the broker catches it. Checks that only look at the final number would wave it through.
03Who the gates protect
A wrong per-unit price isn't an abstraction: today's S$2.0M of subscriptions would buy the wrong number of units — new money short-changed, or old money diluted. Held is an inconvenience; wrong is irreversible.
Plain-language key (NAV, mark, reconciliation, odd lot, bps, gate)
- NAV
- Net asset value — what the fund is worth tonight; divided by units, the price investors deal at.
- Mark
- The price used to value a position at the close.
- Reconciliation
- Proving the fund's own records match the broker's — positions, cash and today's trades.
- Odd lot
- A small share-count difference. Immaterial in dollars; fatal to certification.
- bps
- Basis points — hundredths of a percent. 100 bps = 1%.
- Gate
- A check that must pass before the number leaves the desk. Fail one and the close is HELD, not sent late-and-wrong.