MongoDB Index Not Created After MongoTemplate.insert(batchToSave, entityClass)

I have the following model class:

public class Price extends ModelBase<Price> implements Comparable<Price>{
    @Indexed
    @Field("cid")
    private String companyId;

    @Field("dt")
    private LocalDate date;

    @Field("cp")
    private double closePrice;

    @Field("vl")
    private double volume;

   ...

}

With indexed 'cid', unfortunately when I run 'db.price.getIndexes()' from the mongo console I get:

> db.price.getIndexes()
[
        {
                "v" : 1,
                "key" : {
                        "_id" : 1
                },
                "name" : "_id_",
                "ns" : "th.price"
        }
]

Which means that 'cid' has not be used as index.

Pices are inserted in batch using MongoTemplate.insert(batchToSave, entityClass)

Is this the reason of this issue? Can I insert multiple prices at once and index the documents at the same time?