Investing.com -- Stocks in focus in premarket trade on Thursday, September 28th. Please refresh for updates.

• Micron (NASDAQ: MU) shares slumped after it delivered an earnings forecast for its fiscal first quarter that missed analysts' expectations. However, Micron guided for revenue of $4.40 billion -- plus or minus $200 million -- in its current quarter, topping projections of $4.20B.


• Peloton Interactive (NASDAQ: PTON) shares jumped after the exercise equipment firm announced a five-year partnership with athleisure brand Lululemon (NASDAQ: LULU).


• Apple (NASDAQ: AAPL) shares are trading modestly lower following a report in the Wall Street Journal that the new high-end versions of the tech giant's iPhone 15 are facing overheating issues.


• Accenture (NYSE: ACN) shares dipped after the IT services group unveiled full-year earnings and first-quarter revenue guidance that missed expectations.


• CarMax (NYSE: KMX) shares tumbled after the used-car retailer reported weaker-than-anticipated quarter profit due to slipping demand for pre-owned vehicles.


• Workday (NASDAQ: WDAY) shares slid after the software group said it expects annual subscription revenues to grow by 17% to 19%, which was below analyst estimates cited by Bloomberg News.


• Gritstone (NASDAQ: GRTS) shares surged after the American biotech group won a $433 million contract from the U.S. government to conduct a mid-stage study of its mRNA COVID-19 vaccine candidate.