Utilize the input text as a context reference, choose the right relationship between Lehman Brothers and investment bank 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.

Another answer lies in shifting investor expectations of market shocks, five years after the U.S. "flash crash" that briefly wiped out nearly $1 trillion in market value and seven years after the subprime crisis pushed investment bank Lehman Brothers into bankruptcy and redrew the financial landscape.

Answer: product_or_material_produced