def fetch(self):
        """Unfortunately, IEX's API can only retrieve data one day or one month
         at a time. Rather than specifying a date range, we will have to run
         the read function for each date provided.

        :return: DataFrame
        """
        tlen = self.end - self.start
        dfs = []

        # Build list of all dates within the given range
        lrange = [x for x in (self.start + timedelta(n)
                              for n in range(tlen.days))]

        mrange = []
        for dt in lrange:
            if datetime(dt.year, dt.month, 1) not in mrange:
                mrange.append(datetime(dt.year, dt.month, 1))
        lrange = mrange

        for date in lrange:
            self.curr_date = date
            tdf = super(MonthlySummaryReader, self).fetch()

            # We may not return data if this was a weekend/holiday:
            if self.output_format == 'pandas':
                if not tdf.empty:
                    tdf['date'] = date.strftime(self.date_format)
            dfs.append(tdf)

        # We may not return any data if we failed to specify useful parameters:
        if self.output_format == 'pandas':
            result = pd.concat(dfs) if len(dfs) > 0 else pd.DataFrame()
            return result.set_index('date')
        else:
            return dfs