[{"balance":"5",address:"dom.com",symbol:"xy"},{"balance":"12",address:"xx.com",symbol:"xy"},{"balance":"7",address:"yy.com",symbol:"zz"},{"balance":"1",address:"ee.com",symbol:"zz"},]

db.collection.aggregate([{$match:{address:{$in:["xx.com","yy.com","ee.com","dom.com"]}}},{$group:{_id:"$symbol",sum:{$sum:{"$toInt":"$balance"}}}}])