Embattled grocery giants, whose margins are being squeezed by price cuts and competition from hard discounters Aldi and Lidl, top the FTSE 100 risers leaderboard. Bombed-out Morrisons (MRW) bounces 4% higher to 213.5p, heavily-shorted Sainsbury's (SBRY) skips 3% higher to 342.7p, while Tesco (TSCO) ticks 1.7% higher to 307.7p.

Online domestic appliances retailer AO World (AO.) edges up 2.5p to 238p on its move into the TV market ahead of the World Cup in Brazil. Consumers are widely expected to upgrade to bigger screens and high definition picture quality and the controversial recent float is selling products from the big four TV manufacturers Samsung, Sony, LG and Panasonic.

Energy saving technology microcap LED International (LED:AIM) crashes 75% to 4p on fresh funding problems that could spell the collapse of the company. The shares have lost almost 99% of their value since hitting 340p in 2009.

European floorcoverings distributor Headlam (HEAD) heads 3.6% higher to 489.63p on a strong trading statement, as flagged  by Shares at the start of the month. The Birmingham-based business flags improved trading in the first four months of 2014 and says internal profit targets for the year could be beaten. We take a closer look at events in this story.

Unconventional and conventional hydrocarbons play Falcon Oil & Gas (FOG:AIM) dives 15.9% to 7.25p on a disappointing update from its Mako Trough acreage onshore Hungary. More detailed analysis can be found here.

FTSE 100 testing giant Intertek (ITRK) falls 5.9% to £29.07 after saying that growth has been hit by weak energy infrastructure markets.

Education technology specialist Tribal (TRB) slumps 7% to 184p after warning that delays in closing some 'important' contracts and software installations will cause profits to be second-half weighted. The markets hates such announcements as it raises the risk that full-year earnings forecasts won't be achieved if there's any further delays.

US oily Caza Oil & Gas (CAZA:AIM) gains 16.1% to 17.1p as investors continue to react to yesterday's strong first quarter update. Revenue from oil and gas sales for the first three months of the year surged by 259% to $4.6 million.

Two popular technology stocks are putting in rallies today after recent bear raids. Video search engine Blinkx (BLNX:AIM) jumps more than 8% to 72.75p, while insurance claims outsourcer, and FTSE 250 hopeful, Quindell (QPP:AIM) rises 3.6% to 21.5p.

As flagged by Shares earlier this month, challenged soft drinks bottling giant Coca-Cola HBC (CCH) cheapens 9p to £14.38 on disappointing first quarter figures.

Aim-quoted oil and gas producer Petroceltic (PCI:AIM) gains 1.3% to 155p as it announces plans for a $100 million placing alongside 2013 results and says its Ain Tsila development in Algeria will be on stream in 2018 – against previous hopes of a 2017 start-up. Westhouse comments: 'The announcement of the placing and the anticipated delay to first production in Algeria is disappointing but on the other hand, Petroceltic is bringing in a new strategic shareholder and a successful placing will put Petroceltic on a solid strategic footing and will fund the company fully for the foreseeable future.'

Super materials developer Graphene NanoChem (GRPH:AIM) has won a contract renewal worth an estimated €45 million a year with a major oil industry customer. The deal has been extended from February 2015 to December 2015, advancing the shares 1.4% to 73p.

Testing kit-maker Akers Bioscience (AKR:AIM) rises 2.7% to 285p after striking a distribution deal with Jai Capital that will see several of its devices sold in India.

Regeneration property company, and running Shares Play of the Week St Modwen Properties (SMP) slips 1.4% to 362.9p on submitting its planning application for the development of the New Covent Garden Market, one of the largest projects in its pipeline.

Residential landlord Grainger (GRI) rises 1.4% to 218p on improving market conditions that are helping boost its net asset value (NAV) 12.4% to 228p in the six months to April. This, along with a £42.8 million profit from asset disposals, funded a 5.5% interim dividend hike to 0.61p a share.

An interim management statement from housebuilder Bovis (BVS) sees shares dip 2.2% to 738.5p despite strong a 78% increase in private reservations as well as a rise in average sales price which is expected to at least cover build cost increases.

Heavy construction specialist Keller Group (KLR) is unable to replicate competitor Kier's (KIE) post interim management statement gains, shares in the former falling 2.2% to 923.5p. That's despite trailing a strong US construction-led performance in the four months from 1 January to mid-May.

Building materials specialist SIG (SHI) slips 04% to 178.3p despite the group's interim management statement revealing a 9.4% jump in revenues in the first four months of the year, with like-for-like sales rising by the same amount.

Issue Date: 16 May 2014