Market Report: Blinkx sees value plummet by £140m in 24 hours

You have to pity Blinkx: the AIM-listed advertising technology company ended the day worth almost £140m less than it had been 24 hours earlier.

The catalyst? A warning that earnings before exceptional costs for the first half are likely to be $5m less than expected – around $40m (£23m) – due to tough market conditions. It might not seem like much, but confidence in the company was already shaky.

In January the Cambridge-founded outfit, which does video advertising and other online ads, was the target of a tendentious blog post penned by a Harvard professor that cleaved a third off the company’s value and sowed the seeds of doubt among investors. Despite a robust refutation of all charges from the company, Blinkx has failed to recover and yesterday lost a further 34.25p to 31.5p.

Markets in Asia and the US are booming, but the FTSE 100 recorded slightly more modest gains, up 13.45 points at 6,816.37. Companies trading ex-dividend pegged back the rise, with Royal Mail off 12.1p at 479.1p and Burberry falling 19p to 1,460p.

Ocado slipped 4.3 per cent on Tuesday after warning of tough market conditions. But the online grocer roared 48.8p higher to 403.8p yesterday thanks in part to a Deutsche Bank upgrade to hold from sell.

The bank reckons there’s little downside to its 330p target price.

Michael Spencer’s children were handed close to £200,000 worth of shares in their father’s broking business Icap yesterday, triggered by the coming of age of Mr Spencer’s youngest child. Icap, which was trading ex-dividend, lost 5.6p to 376.6p.

Graphene Nanochem hailed the first commercial deployment of the “wonder material” graphene. The AIM-listed company has signed a £1m contract with an unnamed oil operator for its drilling fluid PlatDrill. Graphene Nanochem added 8.5p to 59p.

Fibre optic cable and satellite technology specialist Global Invacom had a strong start on AIM, climbing to 20.62p after listing at 19.75p. The company raised £11.8m on a £60m valuation.