With the following $match statement;

{
  code: 'test',
  owner: ObjectId('5c6cc364cadec30a2b082cef'),
  tradedate: {
    $gte: ISODate('2015-12-21')
  }
}

an error "Expected end of input but "}" found." is presented.

In MongoDB CLI, an aggregate with the same $match condition preduces correct results.