TOP TIERMARKET NEWSWIRE
Movers explained · September 13, 2026

Why Is COSTAR GROUP INC (CSGP) Stock Moving Today?

By the Top Tier Newswire AI Desk · August 20, 2026 at 10:45 AM ET · reviewed against 0 wire stories

COSTAR GROUP INC (CSGP) is drawing unusual attention today.

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Why CSGP stock is down today

CoStar Group Inc. shares fell 5.68% to $31.82 in early trading on Tuesday, marking a sharp reversal from recent performance. The stock opened near $33.73 but quickly declined throughout the session, hitting a low of $31.75 before closing the day at $31.85. The drop comes amid a mix of analyst activity and insider trading, as well as broader market dynamics affecting the stock.

What Happened

The stock’s decline followed a recent period of volatility, including a 52-week high of $91.89 and a low of $25.89. Recent analyst activity has been mixed, with Citigroup downgrading the stock to Neutral and lowering its price target to $33. Meanwhile, Citizens maintained a Market Outperform rating but also cut its price target to $35. These adjustments reflect ongoing uncertainty about CoStar’s valuation and growth potential. Additionally, Tiger Global Management sold its holding in CoStar, signaling a shift in institutional sentiment. On the insider front, several executives sold shares, including Chief Accounting Officer Cann Cynthia Cammett and Director Hill John W. Founder and CEO Andrew C. Florance, however, bought shares on August 4, indicating some internal confidence.

What The Data Shows

The stock’s intraday performance showed a weak session, with volume at 1.5 million shares, just 20% of the 3-month daily average. The price trend has been volatile, with one fresh 52-week high and 10 fresh 52-week lows recorded on August 20. CoStar’s fundamentals remain mixed: it has a high P/E of 190.4 and a net margin of 2.1%, but revenue has grown 22% in the trailing twelve months. Short-term sentiment appears to be improving, with a 30-day average of 57/100, up from 53/100 a week earlier.

What To Watch

With no upcoming earnings date provided, investors should monitor the breadth of analyst coverage and any further institutional or insider trading activity. The stock’s performance may also be influenced by broader market trends and developments in the real estate tech sector.

AI-assisted analysis composed exclusively from headlines and data on the Top Tier newswire. Public view is delayed 4 hours from real time. Not financial advice.

CSGP by the numbers

Mkt cap: $12.7BP/E: 190.452w: $25.89 to $91.89
CSGP · Aug 20 session (5-min) · -3.35% vs prior close · updated 8:58 PM ET
$31.64$32.77$33.90prev close $33.73$32.607:00 AM9:56 AM12:52 PM3:48 PM6:45 PM7:00 AM · $33.737:05 AM · $33.757:15 AM · $33.787:25 AM · $33.787:30 AM · $33.778:15 AM · $33.508:25 AM · $33.508:35 AM · $33.508:40 AM · $33.509:25 AM · $33.509:30 AM · $33.559:35 AM · $33.069:40 AM · $33.259:45 AM · $33.539:50 AM · $33.039:55 AM · $32.9810:00 AM · $32.5210:05 AM · $32.1710:10 AM · $32.0510:15 AM · $32.0910:20 AM · $31.9310:25 AM · $31.9210:30 AM · $31.8810:35 AM · $31.9410:40 AM · $31.8410:45 AM · $31.8810:50 AM · $31.7610:55 AM · $31.7811:00 AM · $31.8911:05 AM · $31.8611:10 AM · $31.8811:15 AM · $31.9511:20 AM · $32.1811:25 AM · $32.1611:30 AM · $32.1111:35 AM · $32.1511:40 AM · $32.0511:45 AM · $32.0211:50 AM · $32.0511:55 AM · $32.0812:00 PM · $32.4012:05 PM · $32.4012:10 PM · $32.3912:15 PM · $32.3412:20 PM · $32.2212:25 PM · $32.2712:30 PM · $32.2212:35 PM · $32.1612:40 PM · $32.2412:45 PM · $32.2312:50 PM · $32.3012:55 PM · $32.301:00 PM · $32.251:05 PM · $32.241:10 PM · $32.201:15 PM · $32.311:20 PM · $32.241:25 PM · $32.291:30 PM · $32.341:35 PM · $32.291:40 PM · $32.321:45 PM · $32.351:50 PM · $32.331:55 PM · $32.302:00 PM · $32.282:05 PM · $32.282:10 PM · $32.262:15 PM · $32.302:20 PM · $32.342:25 PM · $32.372:30 PM · $32.342:35 PM · $32.302:40 PM · $32.342:45 PM · $32.452:50 PM · $32.492:55 PM · $32.443:00 PM · $32.453:05 PM · $32.413:10 PM · $32.413:15 PM · $32.413:20 PM · $32.513:25 PM · $32.533:30 PM · $32.603:35 PM · $32.623:40 PM · $32.593:45 PM · $32.483:50 PM · $32.563:55 PM · $32.264:00 PM · $32.264:20 PM · $32.265:05 PM · $32.666:45 PM · $32.60

The headlines behind the move

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More on CSGP: full news and sentiment history. Sentiment scores are AI-derived research signals, not financial advice.

Earlier CSGP move explainers: 2026-08-20