[source, ruby]
----
response = client.search(
  body: {
    size: 0,
    aggregations: {
      my_date_histo: {
        date_histogram: {
          field: 'date',
          calendar_interval: '1M'
        },
        aggregations: {
          the_sum: {
            sum: {
              field: 'price'
            }
          },
          the_moving_sum: {
            moving_fn: {
              buckets_path: 'the_sum',
              window: 10,
              script: 'MovingFunctions.stdDev(values, MovingFunctions.unweightedAvg(values))'
            }
          }
        }
      }
    }
  }
)
puts response
----
