Check out the companies making headlines after hours. Discover Financial Services — 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 — 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 — 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. Talos Energy — Shares of the oil and gas company dropped 5% after Talos Energy issued fourth-quarter revenue guidance in the range of $380 million to $395 million, compared to the $393.5 million expected by analysts polled by FactSet. It also announced an underwritten public common share offering of $300 million and plans to use the net proceeds to fund part of its acquisition of QuarterNorth Energy. Plug Power — The developer of hydrogen fuel cell systems plunged about 15% after Plug Power disclosed a $1 billion sales agreement in common stock with B. Riley Securities. It closed Wednesday at $2.74 per share.