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