One cohort of startups as a unit chart, one dot per company.
plotOptions.unit.transition: 'identity', which keys each dot by
its company name: a specific startup keeps its colour and glides across every
regroup, re-bin and resize rather than fading out and back in. Switching view
is a plain chart.updateOptions(view) call. Cluster labels can sit
above or below via clusterLabels.position: the sector labels
curve over the top, the stage-bar labels sit below. The unit chart is a premium type; without a
license it renders with a trial watermark.