Stocks making the biggest moves after hours

$Discover Financial Services (DFS.US)$
— Shares dropped nearly 7% after Discover Financial Services reported fourth-quarter results. The financial services company reported quarterly revenue of $4.20 billion that topped estimates of $4.10 billion, according to analysts polled by LSEG. GAAP earnings of $1.54 per share were not immediately comparable.

$Alcoa (AA.US)$
— Shares dropped nearly 3% after the aluminum producer reported fourth-quarter results. Alcoa posted a narrower-than-expected adjusted loss of 56 cents per share, compared to an expected loss of 86 cents per share, according to analysts polled by LSEG. Revenue of $2.60 billion came in line with estimates.

$H.B. Fuller (FUL.US)$
— H.B. Fuller shares slid about 1%. For the fourth quarter, the company posted adjusted earnings of $1.32 per share, better than the FactSet consensus estimate of $1.27 per-share earnings. Revenue of $902.9 million came in lower than the expected $929.9 million.