In the context of the input sentence, determine the relationship between 'Warren Buffett' and 'Berkshire Hathaway'.
Options: owned by, stock exchange, owner of, industry

For example, two notable value investors operate businesses that fall into this category -- Tom Gayner at Markel and Warren Buffett at Berkshire Hathaway ( NYSE:BRK-A ) ( NYSE:BRK-B ) .
owner of