Stocks making the biggest moves after hours: Costco, DocuSign, Scholastic

Here are the stocks making notable moves in extended trading:

Costco — The wholesale membership club retailer was down about 2.8% after hours Thursday before reporting fiscal fourth quarter earnings post-market.

DocuSign — Shares were up 1.7% after the technology company named former Google executive Allan Thygesen its new CEO.

Guidewire — The software maker rose 0.9% after authorizing a $400 million buyback.

Scholastic — The education company fell 2% after reporting an 82% decline in fiscal first quarter operating income and 74% lower earnings before taxes. Revenue grew 1%.