Dow tumbles more than 600 points on heightened fears of a Russian invasion of Ukraine

• Dow industrials dropped more than 600 points Thursday on Russia-Ukraine war fears.
• President Biden sees a "very high" risk of Russia invading Ukraine in the coming days.

US stocks sank Thursday, with Wall Street's sell-off hitting technology shares the hardest as President Joe Biden and other Western leaders warned that Russia looks set to invade Ukraine.

The Nasdaq Composite, home to the US market's largest technology shares, fell by nearly 3% while the Dow Jones Industrial Average lost more than 600 points, leaving each index down for a second straight day. The information technology sector led losses on the S&P 500 index.

The sell-off picked up pace toward the end of the session. Investors during the day heard President Biden tell reporters there is a "very high" risk of Russia soon invading the former Soviet republic, overshadowing strong earnings reports earlier Thursday.

"My sense is this will happen in the next several days," Biden said outside the White House on Thursday.

Here's where US indexes stood at 4:00 p.m. on Thursday:

• S&P 500: 4,380.26, down 2.12%
• Dow Jones Industrial Average: 34,312.03, down 1.78% (622.24 points)
• Nasdaq Composite: 13,716.72, down 2.88%

Stocks fell throughout the session following a flurry of headlines from Europe chronicling worsening conditions in the standoff between Russia and Ukraine as the latter holds aspirations of joining NATO.

Ukraine on Thursday accused Russia of "provocative shelling," while militants backed by Russia accused Ukraine of aggression. Earlier this week, Russian President Vladimir Putin said certain groups of troops would return to their bases.

"Despite Moscow's claims, we have seen no signs of withdrawal or de-escalation so far. On the contrary, Russia's build-up appears to continue," Jens Stoltenberg, NATO's secretary general, said at a press conference Thursday.

On the Dow, Walmart shares climbed after the retailer raised its annual dividend and backed its long-term outlook for adjusted earnings growth in the face of high inflation. Its fourth-quarter earnings and revenue also surpassed Wall Street's targets. Cisco shares also rose after an earnings beat and a positive forecast.

From the economic data front, weekly US jobless claims rose by 248,000, which was more than expected, and manufacturing activity in the Philadelphia region weakened more than expected in February.

Outside the indexes, DoorDash soared following a record number of quarterly food-delivery orders and monthly active users, indicating people are still getting take-out meals even as pandemic-related restrictions have eased.

Billionaire investor Carl Icahn warned red-hot inflation spells trouble for markets, saying the government is incapable of controlling price increases.

Oil prices fell. West Texas Intermediate crude dropped 2% to $91.68 per barrel. Brent crude, the international benchmark, lost 2% at $92.92.

Gold ran up 1.5% to $1,898.63 per ounce. The 10-year yield fell 8 basis points to 1.965%.

Bitcoin dropped 6.8% to $40,953.08.