https://codepen.io/anon/pen/mjRrZp?editors=0010

grafico correto

var canvas = document.getElementById("barChart");
var ctx = canvas.getContext('2d');

// Global Options:
Chart.defaults.global.defaultFontColor = 'black';
Chart.defaults.global.defaultFontSize = 16;

var data = {
  labels: ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"],
  datasets: [{
      label: "Stock A",
      fill: false,
      lineTension: 0.1,
      backgroundColor: "rgba(225,0,0,0.4)",
      borderColor: "red", // The main line color
      borderCapStyle: 'square',
      borderDash: [], // try [5, 15] for instance
      borderDashOffset: 0.0,
      borderJoinStyle: 'miter',
      pointBorderColor: "black",
      pointBackgroundColor: "white",
      pointBorderWidth: 1,
      pointHoverRadius: 8,
      pointHoverBackgroundColor: "yellow",
      pointHoverBorderColor: "brown",
      pointHoverBorderWidth: 2,
      pointRadius: 4,
      pointHitRadius: 10,
      // notice the gap in the data and the spanGaps: true
      data: [65, 59, 80, 81, 56, 55, 40, ,60,55,30,78],
      spanGaps: true,
    }, {
      label: "Stock B",
      fill: true,
      lineTension: 0.1,
      backgroundColor: "rgba(167,105,0,0.4)",
      borderColor: "rgb(167, 105, 0)",
      borderCapStyle: 'butt',
      borderDash: [],
      borderDashOffset: 0.0,
      borderJoinStyle: 'miter',
      pointBorderColor: "white",
      pointBackgroundColor: "black",
      pointBorderWidth: 1,
      pointHoverRadius: 8,
      pointHoverBackgroundColor: "brown",
      pointHoverBorderColor: "yellow",
      pointHoverBorderWidth: 2,
      pointRadius: 4,
      pointHitRadius: 10,
      // notice the gap in the data and the spanGaps: false
      data: [10, 20, 60, 95, 64, 78, 90,,70,40,70,89],
      spanGaps: false,
    }

  ]
};

// Notice the scaleLabel at the same level as Ticks
var options = {
  scales: {
            yAxes: [{
                ticks: {
                    beginAtZero:true
                },
                scaleLabel: {
                     display: true,
                     labelString: 'Moola',
                     fontSize: 20 
                  }
            }]            
        }  
};

// Chart declaration:
var myBarChart = new Chart(ctx, {
  type: 'line',
  data: data,
  options: options
});

setTimeout(function(){
  data.datasets[0].hidden = true;
   console.log(myBarChart.update({
    duration: 800,
    easing: 'easeOutBounce'
   }))
},3000)