By Liz Moyer

Investing.com -- U.S. stocks were mixed on Friday as stocks were on track to end their worst month since March 2020. Here are the midday movers for Sept. 30:

• Carnival Corporation (NYSE: CCL) shares fell 20% after it said higher costs because of inflation were weighing on results. Bookings are up since Covid restrictions were relaxed but the cruise operator sees fourth-quarter bookings below 2019 levels and at lower prices. Norwegian Cruise Line Holdings Ltd (NYSE: NCLH) shares fell 15% and Royal Caribbean Cruises Ltd (NYSE: RCL) shares fell 11.9%.
• Nike Inc (NYSE: NKE) shares fell 12% after the athletic apparel maker said margins were being squeezed by the discounts it's offering to clear its inventory.
• Apple Inc (NASDAQ: AAPL) shares are down 1% again on Friday after falling all week on worries about demand for its iPhones. The shares were on track to end the week down 6%.
• Tesla Inc (NASDAQ: TSLA) stock rose 0.5% as the electric vehicle maker prepared for its artificial intelligence presentation. Analysts expect to hear more about its full self-driving technology.
• Cineworld Group (LON: CINE) shares fell 19% after the theater chain operator, which recently filed for bankruptcy, said it expects admissions to remain below pre-pandemic levels in fiscal years 2023 and 2024.