Supplying parts for iPhones, iPads and other super-desirable techie products isn't always a licence to print money, it appears. The supplier AZ Electronics' profit warning sent shockwaves across the market and the shares were jolted to the bottom of the mid-tier index.
The company said an "unfavourable product mix", a fall in demand for a camera phone cleaner, and lower than expected sales in the first quarter meant that profit margins were "lower than normal".
This isn't what shareholders like to hear, and despite many analysts explaining the glitch as a "short-term" problem, investors departed and the shares fell nearly 35 per cent, or 129p, to 240p.
The group, which makes the chemicals in electronic screen displays, listed in November 2010 at 240p a share. It said that turnover fell 2 per cent at $179.9m (£117.5m), the second year in a row of declining sales.
But analysts at N+1 Singer Capital Markets said: "We believe that a number of the challenges are likely to be short-term in nature, and note management's continued guidance of a stronger second-half performance."
Analysts at UBS put their rating under review after the profit warning, and said: "AZ is facing some company specific challenges" but said "recovering margins from this level we believe is possible but will depend on the success of new products."
No further news on Cyprus and encouraging UK data from the Rics house-price survey and the British Retail Consortium retail sales monitor, the FTSE 100 gained as investors returned. It rose 36.27 points to 6,313.21.
The weakest blue chip was the drinks giant Diageo. A number of analysts upped their target prices, with Jefferies raising it to 2,300p with a buy. Nomura, which admitted that valuations of beverages stocks are very high, gave it a 2,400p price target and a buy rating. But the spirits group, which makes everything from Guinness to Smirnoff vodka and Johnnie Walker whisky, trickled down 51.5p to 1,965.5p, with traders explaining the fall as profit-taking after a "such a strong run".
A weaker-than-expected Chinese inflation number and good results from the US giant Alcoa, considered a bellwether for metal demand, helped to prop up mining stocks.
Top of the benchmark index was Vedanta Resources, boosted by news that its subsidiary Cairn India had found more oil in India. It lifted 56p to 1,116p on news of the Rajasthan discovery.
The Kazakh miner ENRC has previously suffered after write-downs and problems on production, and declined 36 per cent over two weeks in March, but recent analyst upgrades and "bottom-fishing" from investors looking for a bargain have pushed it up more than 15 per cent in a week, and the shares added 12.7p to 260p.
Rio Tinto, up 143.5p to 3,135p, got a boost from analysts at UBS, who upped their target price for the shares to 4,590p.
UBS also liked the mid-cap Ferrexpo, giving the Ukrainian iron-ore miner a 355p price target. Its shares were top of the tree on the mid table, 29.8p higher at 184.9p. Numis upgraded a raft of miners to Buy, including Tanzania's largest gold producer, African Barrick Gold, whose price target it cut to 250p from 420p. ABG rose 4.9p to 202.1p.
Kenmare Resources was 1.8p better at 30p after the mining and exploration company reported an increase in its ilmenite and zircon production in the first quarter of 2013.
Those whose flutters at the weekend ended up in a torn betting slip after the Grand National boosted bookies, and Nomura thinks William Hill has had a "strong start to the year", increasing its earnings forecast. The broker thinks William Hill "may benefit in 2013 from the probable disruption to Ladbroke's online/mobile roll-out this year".
It retains its reduce stance, but raises its target price to 333p, for shares that dipped 0.4p to 376.3p.
On Aim, the oncology vaccines company Scancell edged up 0.5p to 38p as it appointed the medical expert Peter Allen as a non-executive to its board.
The Mulberry non-executive director Steve Grapstein has bought 10,000 shares, representing 0.02 per cent of the handbag and leather company. The fashion group sashayed up 10p to 960p.