Apple Inc. on Thursday warned that sales for the crucial holiday quarter would likely miss Wall Street expectations, which Chief Executive Tim Cook blamed on weakness in emerging markets and foreign exchange costs.

The disappointing forecast by the world's most valuable technology company helped send shares down as much as 7 percent, taking roughly $70 billion off Apple's market value and forcing that value below $1 trillion. The forecast could also deepen concerns for technology companies that saw a sell-off after misses by Amazon.com Inc. and Google parent Alphabet Inc.

Apple said it expects between $89 billion and $93 billion in revenue for its fiscal first quarter ending in December, with a midpoint of $91 billion coming in below Wall Street expectations of $93 billion, according to IBES data from Refinitiv.