Not a blog. Two pages about the two things a journal could tell you and none of them does, both of which this product now computes.
| What implied volatility did your fill actually pay? | Your broker's export does not contain the answer, and it cannot: no export carries the price of the underlying at the moment your order filled. |
| How many trades before a win rate means anything, and why a day is the unit | The usual answer is a hundred. The usual answer is wrong in a way that matters most to the people who trade most: fifty trades on five days is five pieces of evidence, not fifty. |