algorithmic-trading
4 free lessons tagged algorithmic-trading across Business. Each one is a short sequence of focused steps with narration and a five-question quiz at the end — take them in any order, no signup required.
Costs, Capacity, and a Protocol You Can Trust
The edge that survives statistics still has to survive trading. Spread, market impact and the square-root law, why every strategy has a capital ceiling, and the research protocol that makes a backtest worth believing.
Selection Bias and the Deflated Sharpe Ratio
The statistical core of backtest overfitting: why the best of many trials is inflated even when nothing works, how much to discount it, and why finance needs a far higher significance bar than the usual one.
The Biases That Break It Before Statistics
Look-ahead bias, survivorship bias, and point-in-time data. The errors that make a backtest wrong as a simulation, independent of any statistical question about whether the edge is real.
What a Backtest Actually Claims
A backtest is not a measurement of the past, it is a counterfactual about a world that never happened. Getting precise about that claim explains every way backtests mislead.