* Futures down: Dow 0.61%, S&P 500 1.45%, Nasdaq 2.69%

* Russell 2000 futures fall 1.7%

* Mega-cap tech, chip shares lead selloff

* CBOE Volatility Index at an over one-week high

(Updates with prices, details and analyst comment)

By Johann M Cherian and Twesha Dikshit

June 23 (Reuters) - Futures tracking the tech-heavy Nasdaq

fell more than 2%, leading declines among Wall Street futures on

Tuesday, as concerns over imminent U.S. rate hikes and

debt-backed corporate spending on AI weighed on investor

sentiment.

Stocks across the globe, including those in Europe and Asia,

came under pressure following a selloff on Wall Street in the

previous session, while crude oil and precious metals also fell.

The weakness in U.S. artificial intelligence-related stocks

is likely to persist as investors worry about ballooning

valuations at a time when elevated borrowing costs could make AI

spending more costly.

Mega-cap names came under pressure in premarket trading,

with Nvidia ( NVDA ) and Alphabet down nearly 3% each,

while chipmakers Intel ( INTC ), Marvell Technology ( MRVL ) and

Advanced Micro Devices ( AMD ) dropped between 5.5% and 7.5%.

Shares of Elon Musk's SpaceX were down 4.5%, as it

became the latest megacap to tap the bond market following a

blockbuster IPO earlier this month, even after reporting net

losses in the previous year.

"SpaceX is not yet part of the Nasdaq indexes, but the fact

that it is jumping on the bond train to fund excessive AI and

infrastructure spending revives earlier concerns that Big Tech

may be spending too much on AI infrastructure and increasingly

financing that spending through debt," said Ipek Ozkardeskaya,

senior market analyst at Swissquote Bank.

At 04:39 a.m. ET, Dow E-minis were down 318 points,

or 0.61%, S&P 500 E-minis were down 109.25 points, or

1.45%, and Nasdaq 100 E-minis were down 824.25 points,

or 2.69%.

Futures tracking the rate-sensitive Russell 2000 Index

fell 1.7%. The CBOE Volatility index, Wall

Street's fear gauge, was at an over one-week high, climbing 2.84

points to 20.12.

Traders expect the U.S. Federal Reserve to hike borrowing

costs by a total of 50 basis points by December, according to

the CME Group's FedWatch Tool, up from one 25-basis-point hike

two weeks ago, as investors price in hawkish monetary policy

under new Chair Kevin Warsh.

The yield on the short-term 2-year Treasury note

slipped about 4 bps to 4.19%. In the previous session, the yield

touched its highest point since February 2025.

Concerns over elevated valuations in AI-related names have

resurfaced following a strong rally earlier this quarter in the

aftermath of the Middle East ceasefire.

Chip stocks advanced on Monday, with the Philadelphia SE

Semiconductor Index hitting a record high. Micron's

results on Wednesday could offer some clues into the

outlook for memory and AI chip sector.

Micron tumbled 8.6%, while Sandisk ( SNDK ) and

Western Digital ( WDC ) fell about 9.6% and 6.6%, respectively.

Investors are keeping a wary eye on developments in the

Middle East after the U.S. waived sanctions on Iran for 60 days

after the first round of talks under a nascent peace deal, with

U.S. President Donald Trump saying he will "do what I have to

do" if Iran does not stick to its side of the agreement.

Later in the day, attention will turn to a batch of private

surveys on June business activity, ahead of closely watched

Personal Consumption Expenditures Index, the Federal Reserve's

preferred inflation gauge, on Friday. Economists expect the

price index to come in at about 4.1%, more than double the

central bank's target.