U.S. stock index futures jumped on Wednesday on strong earnings updates from Microsoft and Visa, following a brutal selloff in the previous session that sent the tech-heavy Nasdaq to its lowest close since December 2020.

Growing fears of a global economic slowdown and a more aggressive Federal Reserve pummeled technology and growth stocks on Tuesday, with Tesla's 12% slump weighing the most on the S&P 500 and the Nasdaq.

The sentiment appeared to improve in premarket trading as Microsoft Corp jumped 5% after it forecast double-digit revenue growth for the next fiscal year, driven by demand for cloud computing services.

Visa Inc. rose 5.6% after the payments network said it expects revenue to accelerate past pre-pandemic levels, fueled by a rebound in consumer spending.

However, Google-parent Alphabet Inc. fell 2.8% as slowing YouTube ad sales led the company to report quarterly revenue below expectations.

Nearly a third of the companies on the S&P 500 will report results this week. Facebook-owner Meta Platforms Inc., which will report results after market close, fell 2.1%.

Megacap growth stocks have been battered since the start of the year as investors fear about the impact of higher interest rates, inflationary pressures, geopolitical tensions and China's COVID-19 led lockdown on the global economic outlook.

"I don't think there is confidence right now in renewed leadership [in megacap stocks] but with the declines, there will be attempts to find entry points into some of these major names," said Neil Wilson, chief markets analyst at Markets.com.

The tech-heavy Nasdaq has shed 20.2% so far this year, while the benchmark S&P 500 is down 12.4%.

Nevertheless, overall earnings have been better than expected. Of the 134 companies in the S&P 500 that reported earnings through Tuesday, 80.6% of them have exceeded Wall Street expectations. Typically, only 66% of companies beat estimates.

At 07:01 a.m. ET, Dow e-minis were up 353 points, or 1.06%, S&P 500 e-minis were up 36.75 points, or 0.88%, and Nasdaq 100 e-minis were up 108.5 points, or 0.83%.

Among other movers, toymaker Mattel Inc. climbed 11.3% after a source told Reuters it was exploring a sale.

Audio streaming platform Spotify Technology SA's U.S.-listed shares gained 2.8% after it reported quarterly revenue that beat analysts' estimates on higher advertising income.