Jack Ma’s minute-long video appearance last week gave Alibaba Group Holding Ltd. a much-needed reprieve after months of speculation over the extent to which Beijing will pursue China’s largest online retailer.

But that tonic didn’t last long, as investors returned to grappling with the same questions that had already wiped $150 billion off the firm's market value.

On Tuesday, Alibaba is projected to unveil its slowest pace of third-quarter sales growth in five years while it confronts potentially the biggest crisis of its two-decade existence.