Key Highlights

● CoStar finished among the S&P 500's leading gainers on Friday, October 30, 2026.

● Adjusted Earnings of $0.38 per share beat the $0.34 analyst estimate.

● CoStar raised its full-year earnings outlook for 2026.

● The company agreed to buy Vexcel for about $730 million in cash.

CoStar Group (NASDAQ:CSGP) climbed steeply on Friday, October 30, 2026, finishing among the leading gainers in the S&P 500. The move ran directly against the grain of a session in which technology stocks were hammered and the Nasdaq Composite suffered its worst day since June.

The gain reflected a positive reaction to the company's third-quarter results and its raised 2026 guidance. CoStar, the Arlington, Virginia-based provider of Commercial Real Estate data and online property marketplaces, reported adjusted Earnings Per Share of $0.38, ahead of the $0.34 analysts had expected. The company also lifted its full-year earnings outlook.

A deal on the side

Along with its results, CoStar agreed to buy Vexcel for about $730 million in cash, according to market data. The deal adds to a Business built on detailed property information sold to brokers, investors, lenders and landlords.

The timing of the rally is worth noting. Coverage of the results was dated October 28, indicating the report came earlier in the week, so Friday's gain may have reflected a delayed reaction as investors digested the guidance and the acquisition. The shares rose early in the session and kept building through the afternoon, with the close showing a larger gain than mid-morning readings.

Tech sinks around it

CoStar's advance was all the more striking given the backdrop. The S&P 500 fell 140.32 points to 7,580.07. The Dow Jones Industrial Average lost 572.25 points to 51,770.31, and the Nasdaq Composite tumbled 747.73 points to 25,437.00. The Russell 2000 dropped 47.37 points to 2,811.84.

The selloff began in semiconductors. Intel (NASDAQ:INTC) plunged after issuing a fourth-quarter Revenue forecast of $15 billion to $16 billion, well short of expectations, and warning of cash burn. The Philadelphia Semiconductor index fell to 10,688.80. Amazon (NASDAQ:AMZN)'s report, which showed trailing 12-month free Cash Flow of negative $42.4 billion, added to doubts about the cost of artificial intelligence, as did continued weakness in Alphabet (NASDAQ:GOOGL) a day after its record drop.

Software and internet companies were dragged along. Datadog (NASDAQ:DDOG), AppLovin (NASDAQ:APP), Snowflake (NYSE:SNOW) and MongoDB (NASDAQ:MDB) all fell sharply as investors cut exposure to anything tied to AI spending. A trading specialist said: "A lot of them kind of got ahead of themselves. It's all earnings based and right now, they're not producing,"

Money flowed instead into energy, consumer staples, health care, utilities, materials and real estate, the six sectors that finished higher. The equal-weight version of the S&P 500 fell far less than the standard index, a sign that the damage was concentrated in the largest technology names.

Other forces also weighed on sentiment. West Texas Intermediate crude rose to $104.12 a barrel, crypto stocks slid after Binance was reportedly hacked for about $6.3 billion, and the Federal Reserve, which left its benchmark rate range unchanged on Wednesday, faces growing market expectations of a December hike.

What to watch

For CoStar, attention now turns to execution on the raised 2026 guidance and the integration of Vexcel once the deal closes. Investors will look for signs that the Acquisition strengthens its data offering without adding significant costs.

The broader calendar is crowded. Apple (NASDAQ:AAPL) reports on Monday, November 2, the midterm elections take place on Tuesday, November 3, and the October jobs report is due on Friday, November 6. Those events will help determine whether the rotation away from technology deepens or fades.