Dow plunges more than 600 points as US stocks suffer their biggest drop since June ahead of Fed conference

• US stocks suffered their worst tumble in two months with the Dow sinking more than 600 points.
• Investors are eyeing Fed Chair Jerome Powell's comments at the Jackson Hole conference on Monday.

US stocks suffered their worst tumble in two months on Monday, with the Dow plunging more than 600 points, amid the faltering bear market rally.

Investors are looking ahead to Friday when Federal Reserve Chair Jerome Powell is set to deliver a speech at the central bank's annual conference in Jackson Hole, Wyo.

European energy markets continued to reel, with the continent's natural gas prices soaring 19% following Gazprom's announcement for a three-day Nord Stream 1 closure later this month.

Here's where US indexes stood as the market closed 4:00 p.m. on Monday:

• S&P 500: 4,137.99, down 2.14%

• Dow Jones Industrial Average: 33,063.61, down 1.91% (643.13 points)

• Nasdaq Composite: 12,381.57, down 2.55%

The stock market is on the verge of flashing a sell signal that could lead to a 7% decline, according to Fairlead's Katie Stockton. With the VIX rising, more volatility could loom, she noted.

Warren Buffett's Berkshire Hathaway earned the greenlight to buy 50% of Occidental Petroleum, but he's unlikely to pursue a full takeover at the moment. So far, Buffett's firm has built up a 20% stake.

The euro slipped below parity with the dollar Monday as Gazprom's move heightened recession fears in Europe. At the same time, China's yuan also slipped against the greenback.

Amid the worsening energy crisis, charter rates for natural gas supertankers have surged 124%, as tight supplies ramp up competition for ships, according to the Wall Street Journal.

Meanwhile, the FDIC ordered Sam Bankman-Fried's FTX and other crypto sites to stop telling customers their funds are insured by the federal government. The report came amid a flurry of cease-and-desist letters on Friday.

Oil prices pared losses to trade mixed, with West Texas Intermediate down 0.11% to $90.67 a barrel and Brent crude, the international benchmark, up 0.03% to $96.75 a barrel.

Gold edged lower 0.37% to $1,791.50 per ounce. The 10-year yield rose 4 basis points to 3.029%.

Bitcoin fell 2.28% to $21,030.01.