Utilize the input text as a context reference, choose the right relationship between Apple Inc and Nasdaq 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.

However, after initially rising and helping to lift the Nasdaq in the wake of an Oppenheimer & Co upgrade, shares of Apple Inc ( AAPL.O ) retreated as its performance at the Macworld expo in San Francisco disappointed investors.

Answer: stock_exchange