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# Options Chart

An options chart plots a quantity against *strike price* on a numeric horizontal axis, not against time. The renderer is TVL’s `createOptionsChart`, which is designed for cross-sectional snapshots indexed by strike: option bid/ask curves, implied-vol smiles, open-interest profiles, and gamma exposure.

`tvl.options_chart` supports three series types: `"line"` (default), `"area"`, and `"histogram"`. They share the same axis behavior; only the rendering changes.

## What are options charts useful for?

- **Option price curves**: Plot CallBid/CallAsk across strikes to see the price structure across the chain.
- **Volatility smiles**: Implied vol vs. strike is the “smile” or “skew” chart this rendering is built for.
- **Open interest / volume profiles**: Histogram mode turns the same chart into a strike-indexed bar chart of open interest or daily volume.
- **Gamma exposure**: Net gamma by strike (positive bars above zero, negative below) reads cleanly as a histogram or signed line.

## Examples

### A basic options curve

`tvl.data.options_chain()` is a 21-strike snapshot with columns `Strike`, `CallBid`, `CallAsk`, `PutBid`, `PutAsk`. Point `strike` and `value` at the right columns; defaults pick `series_type="line"`.

```python order=options_chart,data
import deephaven.plot.tradingview_lightweight as tvl
data = tvl.data.options_chain()

options_chart = tvl.options_chart(data, strike="Strike", value="CallBid")
```

A single line traces call bids from the 50 strike to the 150 strike.

### Switch to an area rendering

`series_type="area"` fills the area under the curve. Useful for “stacked” reads of a single quantity (e.g. notional gamma) where the magnitude under each strike matters.

```python order=options_chart,data
import deephaven.plot.tradingview_lightweight as tvl
data = tvl.data.options_chain()

options_chart = tvl.options_chart(
    data,
    strike="Strike",
    value="CallBid",
    series_type="area",
    top_color="rgba(214, 39, 40, 0.5)",
    bottom_color="rgba(214, 39, 40, 0.0)",
    line_color="#d62728",
)
```

The filled area fades to transparent at the bottom; the rim is solid red.

### Switch to a histogram rendering

`series_type="histogram"` renders one bar per strike. Pair it with the `color` parameter and a stronger contrast so the bars register clearly.

```python order=options_chart,data
import deephaven.plot.tradingview_lightweight as tvl
data = tvl.data.options_chain()

options_chart = tvl.options_chart(
    data,
    strike="Strike",
    value="CallBid",
    series_type="histogram",
    color="#9467bd",
)
```

One purple bar rises at each of the 21 strikes.

### Customize color and width (line mode)

`color` is the line CSS color; `line_width` is the integer pixel width (1-4); `title` is the legend label.

```python order=options_chart,data
import deephaven.plot.tradingview_lightweight as tvl
data = tvl.data.options_chain()

options_chart = tvl.options_chart(
    data,
    strike="Strike",
    value="CallBid",
    color="#2ca02c",
    line_width=2,
    title="Call bid curve",
)
```

The line is green, two pixels wide, with a custom legend entry.

### Plot a different value column

The y-axis can be any numeric column. Swap `CallBid` for `PutAsk` (or implied vol, open interest, gamma, whatever your table has) without touching the rest of the call.

```python order=options_chart,data
import deephaven.plot.tradingview_lightweight as tvl
data = tvl.data.options_chain()

options_chart = tvl.options_chart(data, strike="Strike", value="PutAsk")
```

The chart now traces the put-ask curve instead of the call-bid curve.

## API Reference

The horizontal axis represents strike prices (numeric) and the
chart is rendered via the TVL createOptionsChart backend.
For non-strike numeric x-axes (frequency, distance, etc.), prefer
custom_numeric(), which uses the same renderer with a more
descriptive name and parameter (x instead of strike).

**Returns:** `TvlChart` An options chart with a single series.

**Raises:** ValueError -- If series_type is not "line", "area",
    or "histogram".

<ParamTable param={{"module_name": "deephaven.plot.tradingview_lightweight.", "name": "options_chart", "parameters": [{"name": "table", "type": "Any", "description": "Deephaven table with the data."}, {"name": "strike", "type": "str", "description": "Column name for the x-axis (strike prices, numeric).", "default": "'Strike'"}, {"name": "value", "type": "str", "description": "Column name for the y-axis.", "default": "'Value'"}, {"name": "series_type", "type": "str", "description": "\"line\" (default), \"area\", or \"histogram\".", "default": "'line'"}, {"name": "color", "type": "Optional[Color]", "description": "Line / histogram color.  For area series, falls back to line_color when set.", "default": "None"}, {"name": "line_width", "type": "Optional[LineWidth]", "description": "Stroke width in pixels (1\u20134).", "default": "None"}, {"name": "title", "type": "Optional[str]", "description": "Title shown in the series tooltip / legend.", "default": "None"}, {"name": "line_color", "type": "Optional[Color]", "description": "Area-only: explicit line color.", "default": "None"}, {"name": "top_color", "type": "Optional[Color]", "description": "Area-only: top gradient fill color.", "default": "None"}, {"name": "bottom_color", "type": "Optional[Color]", "description": "Area-only: bottom gradient fill color.", "default": "None"}, {"name": "background_color", "type": "Optional[Color]", "description": "Chart background CSS color.", "default": "None"}, {"name": "text_color", "type": "Optional[Color]", "description": "Axis / label text color.", "default": "None"}, {"name": "crosshair_mode", "type": "Optional[CrosshairMode]", "description": "Crosshair mode; see CrosshairMode.", "default": "None"}, {"name": "watermark_text", "type": "Optional[str]", "description": "Single-line watermark text.", "default": "None"}]}} />