They were down around 5% by mid-morning following worse-than-expected results.
Operating profit over the latest quarter dropped to just under $80 million.
That was less than a quarter of the number forecast by analysts, and a fraction of the figure this time last year.
H&M blamed external factors, including the loss of profits previously made in Russia.
The world's second-biggest fashion retailer also faces expenses from a launching a cost-saving program, which includes layoffs.
Savings from the measures are expected to start showing up in the second half of this year.
Higher costs for freight, raw materials and energy also took a toll.
Chief Executive Helena Helmersson said H&M had opted not to pass all those costs on to customers.
Instead, she said the company would keep prices low in a bid to strengthen its market position.
H&M has struggled to keep up with arch-rival Inditex, which owns Zara.
Back in December, it posted a jump in profits, but did say sales growth had slowed towards the end of the year.
