US stock index futures slipped on Monday as climbing Treasury yields and prospects of rising inflation triggered caution over pricey equity valuations, hitting shares of high-flying technology-related companies.

Shares of Apple Inc, Microsoft Corp, Facebook Inc, Alphabet Inc, Tesla Inc, Netflix Inc and Amazon.com Inc resumed their declines from the previous week, falling between 1% and 2.9% in trading before the bell.

A largely upbeat fourth-quarter earnings had powered Wall Street's main indexes to record highs earlier last week, but the rally lost steam on fears of a potential snag in countrywide inoculation efforts and inflation concerns rising from a raft of stimulus measures.

Federal Reserve Chair Jerome Powell in his semi-annual testimony before Congress this week is likely to reiterate a commitment to keeping policy super easy for as long as needed to drive inflation higher.

The Dow closed almost flat for the week on Friday, while the benchmark S&P 500 and the tech-heavy Nasdaq posted their first weekly declines this month.

Cyclical stocks have benefited recently from a rotation out of technology-related shares on hopes that they stand to gain from pent-up demand once the coronavirus pandemic is subdued.

Yields on 10-year Treasury notes have already reached 1.38% , above the psychological 1.30% level.

At 6:53 a.m. ET, Dow e-minis were down 186 points, or 0.59%, S&P 500 e-minis were down 30.5 points, or 0.78%, and Nasdaq 100 e-minis were down 186.25 points, or 1.37%.

Boeing Co dropped 3.9% after a United Airlines plane's engine shed debris over Denver on Saturday, prompting the planemaker to urge airlines to suspend the use of its 777 jets with Pratt & Whitney 4000 engines.

Raytheon Technologies Corp, which owns Pratt & Whitney, also fell 2.9%.