Built on one book, in public, with receipts.
Greeksmith started as one trader's attempt to stop guessing: to write his own rules down — for income, for breakouts, for spreads and hedges — make them executable, and then, the uncomfortable part, measure whether they actually worked.
The measuring turned out to be the product. A signal that "worked 78% of the time" was re-measured against matched days and died. A pattern everyone knows about failed breakdowns turned out to have no edge at all — except at one specific kind of level, where it may. Every one of those findings is on the record, including the ones that cost us features we'd already built.
That's what both products inherit: instruments that state what they see, refuse to overclaim, and publish their own report cards. If that sounds slower than the alternative, it is. It's also the only version worth trusting with your money.