The main US stock measures were trending downwards in Wednesday's premarket activity as traders digest the latest quarterly results of Alphabet (GOOG, GOOGL) and Advanced Micro Devices (AMD).

Standard & Poor's 500 declined 0.5%, the Dow Jones Industrial Average edged down 0.1% and the Nasdaq fell 0.9% before the opening bell. Asian exchanges and European bourses were mixed to lower.

Alphabet's shares dropped 6.6% pre-bell as the Google parent company's fourth-quarter revenue fell short of market estimates. AMD fell 8.9% as the chipmaker forecast a sequential decline in first-quarter revenue. Chipotle Mexican Grill (CMG) slid 5.9% as the burrito chain reported its fourth-quarter results.

Novo Nordisk's (NVO) US-listed stock increased 3.8% before the opening bell as the Danish pharmaceutical company reported its latest quarterly results. Apple (AAPL) was down 2.7% following media reports that the technology giant may face an antitrust probe by China's State Administration for Market Regulation over its app store fees and practices.

Walt Disney (DIS), Boston Scientific (BSX), Uber Technologies (UBER), Fiserv (FI), Emerson Electric (EMR), Johnson Controls International (JCI), Performance Food Group (PFGC), New York Times (NYT), Harley-Davidson (HOG) and Capri (CPRI) report their latest financial results early Wednesday, among others.

Qualcomm (QCOM), Arm (ARM), McKesson (MCK), O'Reilly Automotive (ORLY) and MicroStrategy (MSTR) are scheduled to post earnings after the markets close.

On the economic calendar, the weekly mortgage applications bulletin is out at 7 am ET, followed by the ADP Employment report for January at 8:15 am. The international trade in goods and services report for December posts at 8:30 am.

The January purchasing managers' index composite final report from S&P Global (SPGI) is due at 9:45 am, while the Institute for Supply Management's services index for the same month follows at 10 am. The weekly EIA domestic petroleum inventories report posts at 10:30 am.

Federal Reserve Bank of Richmond President Thomas Barkin is scheduled to speak at 9 am, while Chicago Fed President Austan Goolsbee speaks at 2:30 pm. Federal Reserve Governor Michelle Bowman is slated to speak at 3 pm, while Fed Vice Chair Philip Jefferson speaks at 7:30 pm.

In premarket action, bitcoin moved down 0.5% to $98,227, West Texas Intermediate crude oil decreased 1.2% to $71.82 a barrel, yields on 10-year Treasuries retreated 3.3 basis points to 4.48% and gold rose 0.7% to $2,895 an ounce.