In Stock chart, each stock panel is an instance of AmSerialChart. So you can add ValueAxis pbjects to it like you would normally add to a regular chart.
Each StockGraph is an instance os AmGraph so it has "valueAxis" property.
So adding multiple value axes to a stock panel is just like adding them to a regular basic serial chart. I.e.:
// adding stock panel var stockPanel1 = new AmCharts.StockPanel(); stockPanel1.title = "Value"; // add value axes var valueAxis1 = new AmCharts.ValueAxis(); stockPanel1.addValueAxis(valueAxis1); var valueAxis2 = new AmCharts.ValueAxis(); valueAxis2.position = "right"; stockPanel1.addValueAxis(valueAxis2); // graph #1 var graph1 = new AmCharts.StockGraph(); graph1.valueField = "value"; graph1.lineThickness = 3; graph1.lineColor = "#00cc00"; graph1.useDataSetColors = false; stockPanel1.addStockGraph(graph1); // graph #2 var graph2 = new AmCharts.StockGraph(); graph2.valueField = "volume"; graph2.type = "column"; graph2.showBalloon = false; graph2.fillAlphas = 0.5; graph2.valueAxis = valueAxis2; stockPanel1.addStockGraph(graph2); // set panels to the chart chart.panels = [stockPanel1];
That's it. Now you have two graphs, one attached to left value axis, the other to the right one.
Here's a working demo: http://jsfiddle.net/amcharts/CuhgM/