AWS reported operational issues on Thursday that affected trading on platforms including Coinbase and FanDuel.
The outage was tied to overheating at a data center in AWS's main US-East-1 region hosted in northern Virginia, according to the company.
Full recovery is still expected to take several hours, with efforts slowed due to additional cooling system capacity being brought online.
AWS said it is working to resolve impaired EC2 instances, which provide virtual server capacity.
Coinbase and FanDuel both posted updates on their platforms, citing the broader AWS outage as the cause of extended outages.