Interface CandleUpdate

True when this tick started a new interval bar (append vs mutate-in-place).

True while the bar's open, high, low and volume cover only the ticks this builder has seen. A bar is provisional when it was opened from a tick without the builder having streamed the bar before it: a cold start, or a seed from an older bucket, both of which mean the trades between the bucket's true open and the first tick seen were missed. The close is still the latest price. An authoritative bar for the same bucket, from history, corrects the rest through reconcile.