Wednesday was a good day on Wall Street, with the Nasdaq Composite and Russell 2000 indexes both hitting record highs and other major benchmarks also generally posting solid gains. Optimism about the strong U.S. economy was enough to offset geopolitical concerns related to trade even as White House officials reiterated their position on keeping newly imposed tariffs in place. Some individual companies also had good news that sent their shares sharply higher. Advanced Micro Devices (AMD 3.56%), Nektar Therapeutics (NKTR 3.51%), and Manitowoc (MTW -0.47%) were among the best performers on the day. Here's why they did so well.

AMD chips away at the competition

Shares of Advanced Micro Devices jumped 5.5% after the semiconductor chipmaker presented its menu of expected new products at an industry conference. AMD demonstrated its next generation of CPUs and graphics processors at the Computex conference in Taiwan, including new versions of its Radeon Vega, Ryzen Threadripper, and EPYC processor chips. CEO Lisa Su hailed the company's achievement, saying that new products based on 7-millimeter and 12-millimeter production technology "position AMD to lead the next generation of high-performance computing in markets from premium devices and gaming to machine learnings and the datacenter." AMD shares have now jumped by more than half just since the beginning of April, and many see more good things ahead for the chipmaker.

Open back panel of a Main Gear custom gaming PC featuring a Radeon processor, clearly labeled.

Image source: AMD.

Nektar gets a bounce

Nektar Therapeutics stock rose 7%, regaining a small portion of the ground that the biotech company lost earlier in the week. On Monday, investors punished Nektar shares on new clinical trial data that raised some concerns about whether earlier readings from a key study might have been overly optimistic. Yet since then, bargain-hunting value-seekers have gravitated toward Nektar, arguing that the plunge that slashed as much as 45% off its stock price in a single day had been overblown. As with most biotechs, only time will tell whether Nektar's treatments live up to their full potential, but investors are still trying to make prudent investment decisions despite the volatility.

Manitowoc gets some love

Finally, shares of Manitowoc soared 15.5%. The builder of cranes for construction work got favorable comments from analysts at SunTrust, who upgraded the stock from hold to buy and boosted their price target by $3 to $36 per share. SunTrust believes that Manitowoc appears poised to take advantage of improving conditions in the construction industry, with impressive lineups of new products and an increased capacity for Manitowoc's equipment to use common parts. After having seen strong share-price gains in mid- to late 2017 largely peter out, Manitowoc investors hope that the crane maker will be able to take advantage of stronger overall demand for construction equipment over the long run.