How it works

A stock is a tiny share of a company. Its price moves every day. We draw each day as a little candle. The thick part shows where the price started and ended that day; the thin lines poke out to the highest and lowest points it reached.

The demo runs one trading strategy. It waits for a price to break upward out of a long quiet stretch and bets the move keeps going. That is the Breakout book: a pretend account with an equity curve and every trade it ever made written down.

Next to it sits a second account that makes no decisions at all. It puts the same money into a fixed-rate savings bond, rolls it over when the term ends, and does nothing else, for ever. That is the Bank Savings book, and it is not a second strategy — it is the yardstick. The honest question about any set of trading rules is not “did it make money?” but “did it beat the rate a bank was paying for no work and no risk?”

Everything after this point is one book at a time. Start with the Breakout book — the closing disclaimer is the same whichever you read.

The Breakout book is full of rules, patterns, filters and stops. This one has none. It takes £50,000, puts it in a one-year fixed-rate bond, and rolls it into a fresh one every time the term ends. That is the entire strategy, and it runs itself — nobody picks the rate and there is nothing to fill in.

It is here because the Breakout tab begs a question it cannot answer on its own: was any of the cleverness worth doing? A trading record that is up 4% in a year looks like a success right up until you notice a bank was paying 4.5% for doing nothing at all. Without a yardstick on the same page, a reader has no way to tell the difference — and a demo that quietly leaves that out is not being honest, it is being flattering.

Every month the Bank of England publishes what UK banks were actually paying on one-year fixed-rate bonds. It is official, free, machine-readable and goes back to 2015. That is the number this book uses, and that is why it can run itself for ever without anyone typing anything in.

Each term opens at the rate that had been published by that day — not the figure for that month, which is not out until the month ends. A term opening on 28 July uses June's figure, because July's did not exist yet. The book never uses a number it could not have known at the time, which is the same rule the trading books follow when they refuse to act on a price they have already seen move.

Interest is paid on the interest. That is the whole of it — but it is the reason the line curves upward instead of running straight, and over a long enough stretch the curve is the entire story.

The rate quoted is the AER, which is the honest one: whatever the bank's internal schedule for paying interest, AER is what you actually end the year on. So this book accrues at the AER every day, and after 365 days it has earned exactly the advertised rate — no rounding in its own favour.

Here is where the comparison needs care, because this is the one place the savings book is genuinely worse than the trading book and the numbers do not show it.

The Breakout book is marked to market: its line is what you would have if you sold everything today. This one is not. Until the term ends the money cannot be reached at all without breaking the bond, and breaking a fixed-rate bond early typically costs 90 to 365 days' interest — which on a one-year bond can wipe out most of the gain.

So read the gold line as what the money is earning, not as cash sitting there waiting. The tab says so above the chart, every day, for as long as the term has left to run.

Every rate has a source. Each term records the exact Bank of England series its rate came from and the publication date of the figure it used. Nothing was typed in, so nothing can have been mistyped, and any term on the tab can be checked against the Bank's own published data.

Nothing is erased. Same rule as the Breakout book — no reset button exists anywhere, and the deposits cannot be edited after they are locked. If the rates chosen turn out to have been poor ones, that stays on the page.

Nobody chose it. There is no judgement anywhere in this book — no rate was picked, no provider was preferred, no term was timed. That is exactly what makes it a fair yardstick: it cannot have been tuned, after the fact or before it, to make the Breakout book look better or worse.

It cannot drift. Unlike the trading book, this one stores no daily marks: the whole curve is arithmetic on the deposits, recomputed from scratch on every page load. There is no missed run to catch up and no stored number that can quietly go wrong.

Tax. Every figure here is gross — and so is every figure on the Breakout tab. In reality savings interest above the Personal Savings Allowance is taxed, and trading gains face capital gains tax. Neither book models either, so the comparison between them is fair, but the comparison with your own pocket is not.

Inflation. This is the big one, and it applies to both books equally. Earning 4.12% while prices rise 3% is a real return closer to 1.5%. Every number on this site is what the money grew to, not what it will buy.

And it cannot tell you what to do. A yardstick measures; it does not advise. That the bank may be winning is information, not a recommendation.

The Breakout book turns on one repeated idea — a moving average doing three jobs. This one turns on something simpler: a number you already know.

Everything the trading book does is an attempt to beat a figure that was available, risk-free, on the day they started. That figure is not a detail hidden in a footnote — it is the whole test. So it is printed on this tab, drawn as a gold dashed line across the Breakout chart, and folded into its tooltips, so that at any point in the record you can see not just how it did, but whether it was worth doing.

It's a simulation — a pretend account in a database, showing what a disciplined, rule-following strategy would have done. It is not a prediction of the future, not a tip, and not financial advice. No real money is ever bought or sold. It's here so you can watch an honest, unglamorous strategy play out over time — the wins, the losses, and the long patient waits in between.