Research notes on systematic and algorithmic trading: backtesting, simulation, position sizing, execution and risk, from building and running a live portfolio.https://determinisk.com/https://determinisk.com/research/automated-trading-safeguards/https://determinisk.com/research/automated-trading-safeguards/Letting software trade real money while you sleep is possible, but only once you trust the system, and that trust has to be earned.Mon, 19 Oct 2026 00:00:00 GMThttps://determinisk.com/research/backtest-position-sizing/https://determinisk.com/research/backtest-position-sizing/A backtest's headline return depends on how its trades were sized and how the tool calculates it. Before you trust one, yours or anyone else's, you need to know both.Mon, 19 Oct 2026 00:00:00 GMThttps://determinisk.com/research/backtest-vs-live-trading/https://determinisk.com/research/backtest-vs-live-trading/When the two disagree, one of them is wrong, and finding out which is the most useful test a systematic trader can run.Mon, 19 Oct 2026 00:00:00 GMThttps://determinisk.com/notes/live-pnl-vs-backtest/https://determinisk.com/notes/live-pnl-vs-backtest/Before blaming the market, check whether the backtest and the live system were really doing the same thing. These five are the most common reasons they were not.Mon, 19 Oct 2026 00:00:00 GMThttps://determinisk.com/notes/systematic-trading-research-notes/https://determinisk.com/notes/systematic-trading-research-notes/What these notes are, who they are for, and what I hope comes back from writing them in public.Mon, 19 Oct 2026 00:00:00 GMT