What the data actually says about same-day options trading. Written for traders, readable by humans, and every number comes from real recorded prices.
We measured the spread on S&P 500 daily options every trading day for three years, at every strike, on a CFD dealer and a US exchange. Yes, the CFD dealer charges 5–7× more — except where it doesn't, and except when the exchange gets far worse. The full fee schedule, and the verdict.
We found a strategy with a 91% win rate and a beautiful equity curve. Then we re-ran it at the prices a trader would actually have got, and half the profit vanished. The experiment, in plain English.
You have a trading idea. How do you find out if it makes money before your account does? A step-by-step guide, with a worked example — including the entry hour that quietly loses money every day.