There are a variety of symbol conventions for denoting Berkshire Hathaway Class B shares (CUSIP 084670207). On the IBKR trading platforms, this security is designated by entering BRK, then a space and then B (BRK B). This compares to Bloomberg which uses the convention BRK/B and Yahoo Finance which uses BRK-B.

It should also be noted that this security has been designated as a 10-share unit issue by its primary listing exchange, NYSE Arca, due to its relatively low trading volume. A round lot in this security is therefore set at 10 shares as opposed to the standard round lot unit of 100 shares. If your opening buy or sell order is for an amount less than 10 shares, it is considered an odd-lot and subject to  special handling considerations. Please review our website under the Trading and then Order Types menu options for additional details.