Utilize the input text as a context reference, choose the right relationship between Berkshire Hathaway and insurance from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

The heart of Warren Buffett's Berkshire Hathaway lies in insurance and finance, but a string of massive industrial deals have shifted the balance of the conglomerate's holdings toward industrial and manufacturing firms.

Answer: industry