In the context of the input sentence, determine the relationship between 'Berkshire Hathaway' and 'Warren Buffett'.
Options: currency, founded by, director/manager, position held

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 ) .
director/manager