Having risen as high as 290p over the last year, online grocer Ocado’s shares have slid down to 200p.

That’s still well ahead of the 180p flotation price but sentiment took a knock after last week’s AGM statement revealed likely first-half sales growth of ‘only’ 21%.

Many retailers would be cock-a-hoop to be able to report a similar number but with Ocado, expectations – and the valuation – are high. The market didn’t like the fact that revenues in the second quarter were lower than in the first.

Ocado maintained that the sales pattern was “as expected”, a result both of warehouse capacity constraints and the glut of bank holidays. Apparently bank holidays are not the beanfeasts for online food retailers that they are for bricks-and-mortar supermarkets.

Although there was scepticism from some investors about the second part of the explanation, other grocers – notably Sainsbury’s boss Justin King – have confirmed it as a general experience.

The message must be that Ocado could do a better job of managing expectations. While its bosses might have anticipated the pattern of trading experienced, the share price reaction showed the market hadn’t.

It’s a pity because since its controversial IPO Ocado has successfully confounded many of its doubters, and has even notched up profit at the pre-tax level for the first time – albeit on a quarterly basis.

There is evidence too that Ocado is moving quickly to extend its power beyond its core food offer. The appointment of Simon Belsham, formerly Tesco’s group multichannel development director, as head of non-food looked smart. And the appointment of eBay Europe senior vice-president Doug McCallum as a non-executive also impressed.

After its choppy launch on the public markets Ocado is making progress. There can be little doubt that it’s a business with legs. But the debate about its valuation is not over yet.