Legendary US investor Warren Buffett -- in a 2011 letter to shareholders of his Berkshire Hathaway investment group -- famously compared the entire world's gold stock of 170,000 metric tons, valued at $9.6 trillion (pile A) with another set of assets costing an equal amount (pile B).
Take context from the input text and decide on the accurate relationship between 'Berkshire Hathaway' and 'Warren Buffett' from the options provided.
Options: product/material produced, distributed by, position held, owned by