Sum Aggregation

More info about sum aggregation is in the official elasticsearch docs

A single-value metrics aggregation that sums up numeric values that are extracted from the aggregated documents.

Simple example

{
    "aggregations" : {
        "intraday_return" : { "sum" : { "field" : "change" } }
    }
}

And now the query via DSL:

$sumAggregation = new SumAggregation('intraday_return', 'change');

$search = new Search();
$search->addAggregation($sumAggregation);

$queryArray = $search->toArray();