Thanks for contacting Syncfusion Support. We have analyized your query.
The bubble size can be set according to your requirement.
When there are millions of data, you
can specify the bubble size of first thousand points in a particular size and next thousand points in another size.
We have provided a sample with the datasource containing XValues , YValues and Size of the bubble.
The bubble size also varies according to the chart size. When the width of the chart is less ,the size of the bubble also becomes less due to the responsive behavior of the bubble chart.
Please refer the below sample for your reference WebApplication1
Bubble chart rendered with the size specified in the database with chart width of 1140 px.
Bubble size when the chart width is given as 400px.