JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://www.jqplot.com/src/jquery.jqplot.min.js"></script>
<div id="chart" />

JavaScript

var data1 = [[0, 0], [3, 50]];
var data2 = [[0, 0], [3, -50]];

var offset = 50;

data1[0][1]+=offset;
data1[1][1]+=offset;

data2[0][1]+=offset;
data2[1][1]+=offset;

$.jqplot('chart', [data1, data2], {
    series: [
        {
        yaxis: 'y2axis'}
    ],
    axesDefaults: {
        pad: 0
    },
    axes: {
        yaxis: {
            tickOptions: {
                formatter: formatNegativeOffset
            },
            rendererOptions: {
                forceTickAt0: true
            }
        },
        y2axis: {
            tickOptions: {
                formatter: formatNegativeOffset
            },
            rendererOptions: {
                alignTicks: true,
                forceTickAt0: true
            }
        }
    }
});

function formatNegativeOffset(formatString, value) {
    return value-offset;
}