Utilize the input text as a context reference, choose the right relationship between Hikvision and Hangzhou 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.

In recent months, he has bolstered his stake in Hangzhou Hikvision Digital Technology Co Ltd, the world's largest maker of surveillance cameras that's listed on the Shenzhen Stock Exchange.

Answer: headquarters_location