Lookback

What it does

Reaches back N bars and returns what the source was then — for now-vs-then comparisons.

What happens

Recomputed once per candle from its wired source, incrementally (constant work per bar). It emits no value until the warmup period has passed; after that it produces a value every bar.

When to use

Custom momentum or cross logic (compare the current value to its past self).

Gotchas

• Period can be wired for a dynamic offset; warmup is N bars before it has a value.