Over the past few months, Asos' share price has been more tenuous than fashion's current obsession with pool slides. Having started the year at almost £65, in May it dropped below £39. Here's its year to date:
Why? Mainly because of the online fashion retailer's strong presence abroad, which doesn't hold well with a strong pound.
So it's hardly surprising that this morning the retailer posted a cautious trading statement, showing its margins have been heavily hit by a pound that hit almost 1.7 against the dollar in April. It doesn't make for great reading: although UK sales rose by 43% in the three months to the end of May, international retail sales (which includes the US and territories like Australia as well as Europe) rose by 17% - less than expected.
Investors were clearly spooked: the retailer's shares opened this morning more than 34% lower. It probably doesn't help that in April it posted profits down 22%.
And, given those currency fluctuations, all eyes were on earnings before interest and tax, which were originally expected to be 6.5%, but in the event ended up being 4.5%.
Time was Asos' Big Goal was to hit £1bn in sales, but that's since risen to £2.5bn. So chief exec and founder Nick Robertson put on a brave face when he said 'our profit performance for this financial year is not what we had hoped for due to an unusual combination of factors'. But he added that 'all customer metrics - active customers, new customers, order frequency and units per basket - are positive'.
Asos has been the great success of British online retail, so it'll be interesting to see what becomes of it over the next few years. Fashion is a fickle business, and there are plenty of young pretenders in the market. Its ongoing popularity is by no means guaranteed.