Traders said a number of short sellers had been targetting the company, and the unexpected update had caught them on the hop.
Meanwhile paper maker Mondi issued an unexpected update, saying it expected full year earnings per share to increase by between 20% and 24%.
In an unexpected update, the group said its Napier Brown subsidiary, Europe's biggest non-refining sugar distributor, had filed a complaint to the Office of Fair Trading regarding "an abuse of a dominant position" by British Sugar, which is owned by Associated British Foods, up 26p at £29.93.
Lower down the market French Connection issued an unexpected trading update, and for once unexpected did not mean disappointing.
The publisher of the Daily Mirror and Sunday People saw its share price rise 10.5p, to 186p, at about 9.30am on Tuesday as investors reacted positively to an unexpected financial update for the year to 29 December.
Other telltale signs include receiving unexpected "system update" notifications, prompts to install a new app, or finding apps on your phone that you didn't put there, and a battery that drains more rapidly than normal, adds Aimoto.
Analyst Greg Feehely said: Goal has announced an unexpected trading update (we were recently informed it would be January) detailing the impact on the business of the recent inclement weather.
In an unexpected trading update, A&L said its profits would also take a hit next year after it wrote down the value by £55m of mortgage assets it held in structured investment vehicles (SIVs).
This year, even venture capitalists are joining in: 2000 has been so exciting that Technology Crossover Ventures (TCV), a leading fund responsible in part for such successes as Ariba, ONYX Software, Copper Mountain and RealNetworks, has sent its investors an unexpected "interim update" on the goings-on.
The company's unexpected trading update showed similar themes to Ladbrokes, albeit without the continuing problems the latter faces in its digital business: July's heatwave kept punters away from its shops while when they returned, they were winning their football bets.
It was a somewhat unexpected mid-year update, which elaborated on her annual report published earlier this summer, and discussed the continuing strength of mobile, the skyrocketing adoption of Android phones and iPads, among other things.
