(Updates to afternoon, adds analyst comment)

* Chips resume selloff after short-lived bounce on Monday

* Consumer price data, SpaceX market debut on watch this

week

* Indexes down: Dow flat, S&P 500 down 0.5%, Nasdaq down

1.2%

By Caroline Valetkevitch and Twesha Dikshit

June 9 (Reuters) - The S&P 500 and the Nasdaq indexes fell

on Tuesday as a rebound in technology shares faded and as

President Donald Trump said the U.S. must react to Iran's

shooting down of a U.S. helicopter.

Trump wrote in a social media post that Iran had shot down the

U.S. Apache helicopter that was patrolling the Strait of Hormuz

overnight, and vowed to respond, which added to doubts about

prospects for a truce in the Middle East war.

The Cboe Volatility Index hit its highest level since

April 7 as stocks sold off.

Technology stocks resumed their selloff from Friday

following a bounce on Monday. The S&P 500 tech index

fell more than 4% and was last down 2.9%. The Philadelphia SE

Semiconductor Index also dropped sharply after rising as

much as 3% in early trading. It was last down 3.8%.

"When the bounce ran its course this morning, the tape came

for sale more broadly. There's also a rotation going on ... so

part of it is more of a momentum unwind," said Michael O'Rourke,

chief market strategist at JonesTrading in Stamford,

Connecticut.

Trump's post "created another leg down," he said, but added

that the market is already off its lows of the session.

The Dow Jones Industrial Average rose 15.98 points,

or 0.03%, to 50,801.99, the S&P 500 lost 39.47 points, or

0.53%, to 7,366.26 and the Nasdaq Composite lost 314.38

points, or 1.21%, to 25,615.28.

Investors also appear to be turning cautious ahead of inflation

data and a highly anticipated SpaceX IPO later this week.

Consumer price data for May could offer fresh clues on how the

rise in energy prices, driven by the Iran war, is impacting

inflation. The data is due on Wednesday.

SpaceX's market debut on Friday could also be a hurdle for U.S.

stocks as investors worry about possible overexuberance among

high-growth technology stocks. Elon Musk's SpaceX is aiming to

raise $75 billion and targeting a valuation of $1.75 trillion,

the most ever for an IPO.

Some strategists have said investors are potentially booking

profits in the high-flying semiconductor stocks to make room for

SpaceX in their portfolios.

Technology and AI-linked stocks sold off sharply on Friday

after Broadcom's disappointing forecast fueled concerns about

high valuations in the sector, particularly in chipmakers, which

have rallied strongly this year.

Advancing issues outnumbered decliners by a 1.13-to-1 ratio

on the New York Stock Exchange. There were 189 new highs and 174

new lows on the NYSE.

On the Nasdaq, 2,289 stocks rose and 2,478 fell as declining

issues outnumbered advancers by a 1.08-to-1 ratio. The S&P 500

posted 30 new 52-week highs and 8 new lows while the Nasdaq

Composite recorded 139 new highs and 161 new lows.