Highstock - Single line series-Dynamically create marker based on a trigger

Highstock - Single line series-Dynamically create marker based on a trigger

I am using Highstock - Single line series for plotting
data.http://www.highcharts.com/stock/demo/basic-line. I want to know how
to create marker on certain points based on a trigger.If a sudden increase
happens in y axis,i want create a marker on that point(ie sudden increase
happend from 460 to 470,i want to create a marker on 470).I want to do it
in client level.How can i do this.Can anyone help on this.