March 6 (Reuters) - The Nasdaq Composite

confirmed on Thursday it has been in a correction since peaking

last December, with losses fueled by worries about global trade

and the pricey valuations of Wall Street's AI heavyweights.

With Thursday's 2.6% decline, the index was down a total of

10.4% from its record high close on December 16, meeting a

widely used definition of a correction.

Worries about U.S. President Donald Trump's tariffs have

deepened concerns about inflation and a slowing economy in

recent weeks, hitting shares across Wall Street and pushing all

three major indexes into negative territory for 2025.

U.S. stocks ended sharply lower on Thursday after Trump

exempted goods from both Canada and Mexico for a month from

tariffs he imposed this week, the latest twist in fast-shifting

trade policy that has whipsawed financial markets and business

leaders.

"The Trump bump for equities has now turned into the Trump

slump. Equity markets continue to be in a risk-off mentality on

the combination of market uncertainty and the overall mixed

messages around tariffs emanating from Washington," said Gene

Goldman, chief investment officer at Cetera Investment

Management in El Segundo, California.

The Nasdaq's pullback also reflects mounting concerns about

the valuations of Wall Street heavyweights that have been

spending heavily to dominate AI technology, a key driver of

market gains in recent years.

Shares of Nvidia ( NVDA ) and other chipmakers sank after

Marvell Technology ( MRVL ) gave an in-line revenue forecast

that left investors jittery about spending on AI infrastructure,

the latest sign that optimism about the technology may be

cooling on Wall Street.

As of Thursday's close, the S&P 500 was down almost

7% from its record high close on February 19. The Dow Jones

Industrial Average was down over 5% from its December 4,

2024 record high close.