OptionalcolorMark color; defaults to the target series' color, else a neutral. Shape + label carry the meaning too, so the mark is never color-only (WCAG 1.4.1).
Optionalkindpoint = a diamond on the nearest sample of seriesIndex; rule = a vertical line. Default point.
Short description of the event (announced, shown in the readout, listed in the summary).
OptionalseriesWhich series' nearest sample a point marker sits on. Default 0.
OptionalshowDraw the always-on text label beside the marker. Default true. Set false for dense event
sets (many markers on one chart): the marker still renders and the cursor readout +
screen-reader announcement still surface the label on hover or keyboard select, but the static
label is suppressed so a cluster of events doesn't collapse into overlapping text.
x position (data units) the annotation marks.
An event marker on the time series — a dot on the nearest sample of a series, or a vertical rule, at an x position, with a label (e.g. "GSR +$2.0M"). Events are half the story on a portfolio chart: a climbing line without the allocation markers hides that a jump was new capital, not yield.