Thursday saw an up-and-down session on Wall Street, with most stock indexes ultimately finishing about half a percent higher. Market participants tried to stay focused on positive news, including the completion of the latest round of trade discussions between the U.S. and China, as well as comments from Federal Reserve Chair Jay Powell that pointed toward a less aggressive stance on monetary policy. In addition, there was good news for several individual companies, and Aurora Cannabis (ACB -5.67%), Amarin (AMRN 0.24%), and Constellation Brands (STZ 0.44%) were among the top performers. Here's why they did so well.

Aurora brightens up

Shares of Aurora Cannabis picked up 9% on a good day for marijuana stocks across the market. Investors are still trying to parse through Aurora's expectations for the near future, with the company having said earlier this week that it expects net revenue of $50 million to $55 million during the fiscal second quarter, which ended on Dec. 31. Aurora has boosted its production capacity from 70,000 kilograms per year to 100,000 currently, and it hopes to hit the 150,000-kilogram-per-year mark by the end of March 2019. Moreover, as more mainstream stock analysts start to cover the cannabis space, it's likely that Aurora will attract even more investors as 2019 continues.

Green-colored aurora borealis over a mountain ridge, with Aurora corporate information superimposed.

Image source: Aurora Cannabis.

Amarin keeps climbing

Amarin saw its stock jump another 22%, building on gains from Wednesday as some investors speculated that the company might become the target of a takeover effort. This week's J.P. Morgan Healthcare Conference included a presentation from the fish-oil drug specialist featuring the benefits of its lead drug Vascepa, and investors reacted favorably to the idea that sales of the drug could push Amarin's overall results higher. Today, rumors arose that a major pharmaceutical company might seek to add Vascepa to its stable of approved treatments by buying Amarin outright. With one major M&A transaction already having been proposed in the biopharma space recently, it's entirely possible that another such move could be in the cards.

Check out the latest Amarin earnings call transcript.

Constellation gets back into the sky

Finally, shares of Constellation Brands finished higher by 6%. The beer, wine, and spirits producer suffered huge declines in its share price following the release of its most recent quarterly results, which included a big downward hit stemming from the company's stake in cannabis producer Canopy Growth. Yet investors seemed to consider today that they might have overreacted, and with Canopy showing a second day in a row of big share-price advances, Constellation shareholders appear to have renewed confidence that the company's overall strategy toward consumer goods of all types could prove successful in the long run.

Check out the latest Constellation Brands earnings call transcript.