This has come up enough times so here's our entire explanation in one post.
RNS mentioned press comment on Innsworth class action on 13-Nov-25. Shares didn't move much that day.
RMV fell 12% on 7-Nov, day of trading update.
By 12-Nov, RMV has already fallen \~30% from Aug peak.
In total, RMV is down 47% from Aug-25 peak:
* Class action claim: £1.5bn
* Market cap's fallen £2.9bn, which is much larger than £1.5bn
Now I know:
* Share prices don't move mechanically with news
* Losing class action may mean business practice changes in addition to headline claim
* Some people likely knew about class action early
But, even with these caveats, it is hard to attribute RMV price decline entirely to class action.
Trajectory of Rightmove RMV over the past year is similar to Autotrader $AUTO.
No equivalent class action at Autotrader. (One may argue a RMV loss will force business practice changes at AUTO; that's a stretch)
**AI fears, not class action, is the best explanation for RMV decline.**
PS. I dislike this kind of price "analysis" because, even if my explanation of price moves is entirely correct, market prices can be wrong and they say nothing about how fundamentals will develop over the long term.