Alibaba shares tumbled on Friday (November 19), falling almost 11%.
That after the e-commerce titan slashed its forecast for annual revenue growth as part of results out the previous day.
Alibaba now expects revenue for the year to March to rise no more than 23%.
That would be the smallest gain since its stock-market debut in 2014.
It's also down from an earlier forecast of closer to 30%.
The firm cited headwinds including increased competition, and China's crackdown on its big tech firms.
Chief Executive Daniel Zhang said clothing and general merchandise were among the worst-hit areas.
Established players like Alibaba now have to contend with new entrants into e-commerce, including short-video app Kuaishou.
Such firms are benefiting from regulators' desire to see more competition.
Alibaba has also had to rethink how it works amid increased scrutiny from watchdogs.
This year it toned down its normally much-hyped Singles' Day online shopping extravaganza.
Regulators have called on firms to focus on 'common prosperity', not sales growth.
For the most recent quarter Alibaba reported revenue up 29%, its slowest gain in six quarters.
Including the latest losses, its shares are now down 40% this year.