The stock market got off to a solid start on Monday, bouncing back from small losses early in the trading day to finish with modest gains. Major benchmarks were up less than a quarter percent as market participants kept their eyes on the slowing trickle of third-quarter earnings reports as well as the negotiations related to tax reform in Washington. Some individual stocks logged significant gains. Roku (NASDAQ:ROKU), GGP (NYSE:GGP), and Nektar Therapeutics (NASDAQ:NKTR) were among the best performers on the day. Below, we'll look more closely at these stocks to tell you why they did so well.

Roku wins again

Shares of Roku continued their upward surge from last week, surging nearly 30% to post the stock's third big daily gain in a row as excitement keeps building about the streaming media player manufacturer's prospects. Strong earnings results from Roku ignited the upward move for the stock late last week, and those following the company have marveled at the pace at which CEO Anthony Wood has joined the ranks of technology billionaires. If Roku continues to gain adoption among manufacturers of televisions and other hardware and can keep its advertisers happy, then there's every reason to think that the company can support a healthy share-price valuation.

Roku player and accessories, described against a purple background.

Image source: Roku.

GGP gets an offer

Shares of retail real estate specialist GGP jumped 8% after the company confirmed receiving an offer from Brookfield Property Partners (NASDAQ:BPY) to buy out GGP entirely. Brookfield and its affiliates already own about 34% of GGP's outstanding stock, and the deal would pay remaining shareholders either $23 in cash or 0.9656 Brookfield partnership units for every GGP share they own, subject to a total 50-50 split between cash and stock. GGP said that it would form a special committee to evaluate the deal, but the fact that GGP stock trades above the cash offer price as well as the price of Brookfield units suggests that shareholders of the retail real estate company will want a higher offer before accepting.

Nektar looks for a breakthrough

Finally, Nektar Therapeutics stock climbed 14%, building on gains from last week. The biotechnology company announced on Saturday that the first data from a phase 1/2 study to evaluate Nektar's NKTR-214 investigational cancer therapy in conjunction with Bristol-Myers Squibb's (NYSE:BMY) Opdivo showed promising results. Among the most noteworthy observations were responses across melanoma, renal cell carcinoma, and non-small lung cancer, and a lack of severe adverse events as defined by the study also made Nektar officials happy. Trials will continue, but Nektar is optimistic about early signs from the study.

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