are the bubbles in the bubble chart widget sized proportionate by diameter, radius, or area (to the input value)?

Hi Daniel, The answer is not that strait forward as you would expect and the size is not always proportional. We are using libraries from Highcharts and actually many people ask the same question. There is a nice explanation here on the Highcharts forum: https://www.highcharts.com/forum/viewtopic.php?t=47382