Cumulative Sum¶
Math · Temporal
Running total of a series — at bar i, the sum of values from bar 0 through bar i. Useful for cumulative volume, P&L curves built from per-bar deltas, or any 'so far' metric.
Cumulative Sum keeps a running total: at each bar it outputs the sum of all the source values from the start up to that bar. It's how you turn a stream of per-bar deltas into a cumulative curve — the same operation that turns per-bar P&L into an equity curve, or signed per-bar volume into a cumulative line.
How it works¶
Each bar the block outputs the sum of the source from bar 0 through the current bar. Whatever you feed in gets accumulated; the line only ever rises (when inputs are positive), falls (negative), or holds (zero). Wire a series (or Bars, using close) into the input. There are no parameters — it's a pure running total from the start of the data.
When to use it¶
Use Cumulative Sum to build "so far" curves from per-bar quantities. Feed it signed per-bar volume to construct an OBV-style accumulation line; feed it per-bar returns or deltas to build a cumulative performance curve; feed it any event count to track a running tally. It's the integrator: whenever you have a rate or a delta and want the accumulated total, this is the block.
Example¶
A custom accumulation line: build signed volume (volume × the sign of a Diff of close) and feed it into Cumulative Sum to get a running buy/sell-pressure curve — your own OBV variant. Watch it for divergence against price in the Tester review.
Tips & gotchas¶
- It's the integrator — turns per-bar deltas into a cumulative curve.
- Accumulates from the start of the data — the absolute level is arbitrary; read its direction and divergence.
- No parameters — pure running total.
- Pairs with Diff — Diff differentiates, Cumulative Sum integrates; they're inverses.
Related blocks¶
Inputs¶
| Socket | Type | What to wire in |
|---|---|---|
| In | series / bars |
Source series. BARS input uses close. |
Outputs¶
| Output | Type | Plots as | Description |
|---|---|---|---|
| Σ | series |
Line · sub-pane | Running cumulative sum. |
Reference auto-generated from the block catalog · category Math.