These are my tools: live boards that each answer one practical question. Move a slider and the numbers and the picture follow at once; your settings are kept in the page's address, so a link you copy opens the board exactly as you left it. Under every board you will find how to use it, the equations behind it, a worked example, and the assumptions and limits of what it can tell you. The tools are free and run in your browser. The longer stories are on the Blog, the code I publish as Jupyter notebooks is under Notebooks, and the research papers live under Research.
No. 2
Goal or Blow-Up: The Odds for a Day-Trading Account
How likely am I to reach my goal before I blow up my account, and when?
No. 1
Day-Trading P&L Calculator: One Day to One Year
With my win rate, reward-to-risk and costs, what will a day, a month or a year of trading make — on average, typically, and in a bad year?