Interactive Brokers Group Inc. said it was experiencing difficulties with its trading platform Monday. “We are working to restore services,” the company said on Twitter.

The problems started shortly after 6:30 a.m. in New York, with more than 300 people registering complaints on Downdetector’s website by 9 a.m. Social media postings about the online brokerage increased.

Kalen Holliday, a spokeswoman for the Greenwich, Connecticut-based firm, declined to comment.

Robinhood also reported outages, though the problems apparently were unrelated. Retail trading has surged during the pandemic and Robinhood probably has been the biggest beneficiary.

Bloomberg Intelligence reports that retail equity order climbed to 20% of all orders in the third quarter, up from 15% a year earlier. At some point during the year, most full-service and online brokerages have encountered problems avoiding service disruptions.

This article was provided by Bloomberg News.