The ticker symbol for Berkshire Hathaway Class A shares is BRK.A.
Berkshire Hathaway has two publicly traded share classes. Class A shares trade under BRK.A, while Class B shares trade under BRK.B. The period distinguishes the two symbols; BRKA is not the standard ticker format.
Class A shares are famous for their extraordinarily high per-share price and have never been split. Berkshire created Class B shares in 1996 so investors could buy a smaller economic interest without paying the full price of a Class A share. In 2010, Class B shares underwent a 50-to-1 split connected with Berkshire’s acquisition of BNSF Railway.
A common mix-up is treating BRK.A and BRK.B as interchangeable. They represent the same company but have different prices, conversion rights and voting power. Class A holders can convert into Class B shares, but the reverse conversion is not allowed. Both symbols identify Berkshire Hathaway stock, but BRK.A is the canonical symbol for Class A.