11 lessons
One Sale, Three Statements
Follow a single £100 sale as it ripples through the P&L, balance sheet, and cash flow, and see why they can disagree.
KYC/AML: What Happens to Your Passport Photo After Onboarding
You snapped a selfie and a photo of your passport to open an account in five minutes. That image is now legally radioactive: a bank must keep it for exactly five years, then is required to delete it.
The Audit: What Auditors Actually Do (and Don't)
Everyone thinks the auditor signs off that "the numbers are true." They don't. They promise something far narrower, and the gap between what they promise and what you assume is exactly where Enron and Wirecard happened.
VaR and Stress Testing: What a Bank Could Lose by Tuesday
Every evening a bank produces a single number: the most it expects to lose tomorrow on a bad-but-not-catastrophic day. Then it asks a harder question the number cannot answer: what if tomorrow is catastrophic?
Anatomy of a Flash Crash
At 2:32pm on 6 May 2010 the US stock market began to fall. Twenty minutes later the Dow had swung roughly 1,000 points, shares of blue-chip firms had printed at a penny and at $100,000, and then almost all of it reversed. No news caused it. The plumbing did.
Open Banking: What You Authorize When You Connect Your Bank to an App
You tapped "Connect with Plaid" to link your bank to a budgeting app. In those few seconds you handed over a key to your transaction history, and most people never read what the key actually unlocks.
Sanctions Screening: How a Payment Gets Frozen Mid-Flight
A $40,000 wire leaves New York for Dubai and stops dead at a correspondent bank. Nobody declined it for lack of funds. An automated filter matched a name to a government list, and now the money is legally stuck.
Market Surveillance: Catching Spoofers and Insiders
Every order you place leaves a timestamped fingerprint. Surveillance engines replay billions of them to find the trader who flashed orders he never meant to fill, or who bought just before the news broke.
Tax Withholding on Dividends: The Cross-Border Refund Maze
A Swiss company pays you a dividend and 35% vanishes before it reaches your account. The treaty says you should only pay 15%. Getting the other 20% back can take two years, three intermediaries, and a paper certificate.
Fraud Engines: the 50ms decision that approves or declines your card
Before your bank says "yes" to a £40 tap, a machine has already read 500 things about you and scored the risk, in roughly the time it takes a hummingbird to flap its wings once.
A Day in a Treasury Department
By 9am the corporate treasurer already knows every cent the group holds in 30 currencies, and has decided which is borrowed, which is hedged, and which is parked overnight. Here is how that morning actually works.