What is backfill chart reads and when should I run it?

Backfill chart reads finds past trades that already have a chart image but still have blank Market Context fields, and runs a vision read on each. Up to 20 at a time, because vision is the expensive call.

The counterpart to bulk tagging, for the trades you logged before auto-read was on or before you had a key.

What it selects. Trades with an image attached and at least one blank extractable field — CVD, VWAP, order flow, stop, target. It skips trades already fully filled, and it skips local-only desktop video clips, which the browser cannot reach.

It fills blanks only, the same rule as the automatic read. Nothing you typed is at risk.

Twenty at a time, not fifty. That difference is the whole cost story of this page: an image is worth far more tokens than a note, so the same care that batches tagging in fifties batches this in twenties.

When to run it: after you first add a key, to bring your history up to the state new trades arrive in. And — this is the better reason — after you fill in your context profile. The same images read against your actual chart vocabulary produce meaningfully more, so a backfill run then is worth more than the same run before.

What it will not fix: a trade with no image. There is nothing to read. Those need a screenshot attached first, by hand or by capture.