• Rightmove (RMV LN) short interest climbed from about 2% of float in January to about 12.7% by mid-October, with the biggest step-ups in June, late July, and mid-September.

• Since a £1.5 billion collective action lawsuit was filed in April 2026, short interest has risen from about 3% to 12.7% of float, while active long interest has been sideways and relatively constant.

• Since July, short interest has tracked the UK 10-year gilt yield, a key driver of mortgage rates. The yield has climbed from about 4.5% to 5.4% since January.

• Rightmove operates the UK’s largest online property portal, which matches home buyers and renters with property listings, similar to Zillow in the US.

• The business charges agents and housebuilders subscription fees to advertise their properties on the platform. It accounts for over 80% of time spent on UK property portals.

• The stock fell sharply in February and again in April on the lawsuit, then traded sideways before an August rally, a late-September sell-off, and a mid-October rebound. Short sellers are targeting two risks.

• First, a cooling UK housing market, hit by high mortgage rates.

• Second, the £1.5 billion collective action filed in April 2026 accuses Rightmove of abusing its dominant position by charging estate agents excessive and unfair fees, threatening its pricing power.

• S3’s crowded score measures how crowded the short trade is, on a scale of 0 to 100. It has risen from about 20 to 65, in line with short interest. S3’s squeeze risk measures the risk of a short squeeze. It rises above the crowded score when the stock gains and short sellers lose money, and is now about 85 after the mid-October rebound.

• While the crowded score and squeeze risk rose with the rising short interest, the active long interest in the stock has been sideways without much correlation to the stock price, trading in the 39% to 45% range.

• Rightmove was demoted from the FTSE 100 to the mid-cap FTSE 250 Index in June 2026, after its share price fell more than 40% over the previous 12 months.

• Since July, short interest has tracked the UK 10-year gilt yield. Higher yields push up mortgage rates, which hurts the housing market.

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The information herein (some of which has been obtained from third party sources without verification) is believed by S3 Partners, LLC (“S3 Partners”) to be reliable and accurate. Neither S3 Partners nor any of its affiliates makes any representation as to the accuracy or completeness of the information herein or accepts liability arising from its use. Prior to making any decisions based on the information herein, you should determine, without reliance upon S3 Partners, the economic risks, and merits, as well as the legal, tax, accounting, and investment consequences, of such decisions.