Shares in car parts-to-bicycles seller Halfords (HFD) motored 9% higher to 346.3p on a strong first quarter trading statement. For the 13 weeks to June 28, the £634 million cap reported retail like-for-like sales up 8.8%, with better weather benefiting cycling sales and car maintenance revenues revving up 11.8%. With sales momentum behind Halfords and management actions coming through, Cantor Fitzgerald's Kate Calvert upgrades her rating from 'sell' to 'hold'.

Burberry (BRBY) strutted 4% higher to £14.98 as investors applauded a better-than-expected first quarter trading update from the global luxury leader. Read our thoughts on the £6.3 billion cap here.

A poor trading update has overshadowed a move by Dechra Pharmaceuticals (DPH) to focus on higher-margin products. Its shares collapsed by 8.1% to 685p after flagging US supply issues and bad weather conditions disrupting product deliveries. Yet one analyst reckons it is now a takeover target, as we discuss in more detail.

Satellite operator Avanti Communications (AVN) offered a series of excuses to why revenues will miss by a third this year. Its failure to sign several major contracts in Africa is the key point, and the company goes further, admitting that its key performance indicators have clouded the picture, rather than made it more clear as originally intended. That sent the shares crashing 40% to 150.25p, although chief executive David Williams, buys into the fall, taking his stake to 1.67 million shares, or 1.49% of the company.

Another profit warning from online games developer Zattikka (ZATT:AIM) calls into question its very survival. Gamers are simply not signing up in enough numbers, nor spending enough on gaming upgrades, leaving Zattikka threadbare with cash of £950,000. This has sparked urgent talks with lenders and a rethink over strategy an triggered a 39% collapse in the shares to 17p. Having joined the stockmarket less than a year back at 100p, a crash landing won't surprise Shares readers since we flagged the dangers last August (page 40).

Security group G4S (GFS) was at the mercy of negative analyst comment, sending the stock down 2.4% to 224.1p. Goldman Sachs published a 'sell' note ahead of interim results on 28 August, saying there's risk to profit margins. Panmure Gordon has downgraded earnings on currency issues, cost base concerns, margins and write downs. We flagged the problems facing G4S in an article published in the 4 July issue of Shares.

Bwin.Party Digital Entertainment (BPTY) dipped 5.6% to 123.2p after flagging lower-than-expected margins from its sports betting operation and competition in bingo.

Hovis-to-Bisto brand owner Premier Foods (PFD) baked in a 5.5% gain at 67.75p as investors responded positively to news it is reorganising its milling business, a move involving the closure of its mill in Barry, against a backdrop of market overcapacity.

FTSE 250 African oil explorer Ophir Energy (OPHR) fell 4.5% to 372.2p after announcing an unsuccessful result from its Starfish well offshore Ghana. Its smaller peer Rialto Energy (RIA:AIM), which also had a stake in the prospect, gave up 39.7% to 1.1p.

A board shake-up at Russian oil firm Ruspetro (RPO) has been warmly received by the market, the shares ahead 2% at 30.1p. Key among the changes is the replacement with immediate effect of chief executive officer Don Wolcott by current finance director Tom Reed, the group also agreed in principle to extend the maturities of two shareholder loans with a combined value of $84 million.

North Sea operator Antrim Energy (AEY:AIM) gained 7.4% to 7.25p after announcing the sale of an option to acquire an interest in a Tanzanian project for $7.5 million. The deal boosts the cash balance without a reduction to wells, production, reserves or resources.

Overhyped iron ore explorer Beowulf Mining (BEM:AIM) continued its descent after striking a complicated and unappealing financing deal. The shares fell 10.7% to 6.25p after Beowulf brought in Lanstead as a new investor, providing a drip feed of cash.

Risk management software supplier Lombard Risk Management (LRM:AIM) has unveiled a 'significant contract win' with Israeli bank Leumi Group. No financial details were given but the market liked the news, egging the shares 4.65% higher to 11.25p.

Radiotherapy specialist Advanced Oncotherapy (AVO: AIM) increased by a fifth to 1.9p after announcing a £500,000 equity placing. The 16.6 million shares are being sold at 3p each - an 85% premium to yesterday?s (July 9) closing price.

Veterinary medicine company Animalcare (ANCR: AIM) was up 2.2% to 138.8p after management confirmed the company has met market expectations for the year. In the 12 months to July revenues increase 11% year-on-year, boosted by a 22% annual rise in turnover at its core licensed veterinary medicines business. Its full-year results will be released on 25 September.

Find out how to deal online from £1.50 in a SIPP, ISA or Dealing account. AJ Bell logo

Issue Date: 10 Jul 2013