Stocks making the biggest moves midday:（1）

$3D Systems(DDD.US)$
— Shares dropped 10.2% after the 3D printer maker reported weak first-quarter earnings. 3D systems reported an adjusted loss of 9 per share on revenue of $121 million, while analysts polled by Refinitiv expected a loss of 7 cents per share and revenue of $128 million. The firm also reaffirmed full-year revenue guidance and raised its full-year adjusted EBITDA expectations, while cutting 6% of its workforce.
$Novavax(NVAX.US)$
— The biotechnology stock surged 44% on news of promising vaccine data and a major cost-cutting initiative that includes broad layoffs.
$Skyworks Solutions(SWKS.US)$
-- Shares slid about 6% it posted weaker-than-expected fiscal third-quarter guidance. The semiconductor firm forecasts non-GAAP per-share earnings of around $1.67, lower than consensus estimates of $2.06, according to StreetAccount.
$Under Armour-C(UA.US)$
— The apparel company slipped 5.3% after the company projected earnings per share and revenue to be short of Wall Street expectations for the full-year. But Under Armour was able to beat expectations of analysts polled by Refinitiv on the top and bottom lines for its fiscal fourth quarter.
$Fisker(FSR.US)$
— Shares shed 4.8% after the automotive company's first quarter earnings came in under Wall Street forecasts. Fisker said it lost 38 cents per share, more than the projected loss of 30 cents from analysts polled by Refinitiv.
$Plug Power(PLUG.US)$
— The hydrogen fuel company dropped 14.1% after posting a wider loss per share for its first quarter than analysts expected. Plug Power reported a loss of 35 cents per share, while analysts polled by FactSet anticipated a 26-cent loss. Revenue came in ahead of expectations at $210.3 million against a consensus estimate of $206.9 million.
$Western Digital(WDC.US)$
— The chipmaker's stock dropped nearly 3% after the company posted a wider-than-expected loss for the fiscal third quarter. Western Digital also expects its fourth-quarter revenue to be in the range from $2.4 billion to $2.6 billion, lower than analyst expectations, according to Refinitiv data.
$PayPal(PYPL.US)$
— Shares of the digital payments company shed 11% even after it posted a beat on the top and bottom lines. PayPal lifted its guidance for the full year but shared-weaker-than-expected guidance for the current period.
$International Flavors & Fragrances(IFF.US)$
– Shares fell 7% after the company missed earnings expectations for the first quarter, according to FactSet, and cited impacts from soft end-market demand and customer inventory destocking. Current quarter financial guidance was weaker than Wall Street estimates, according to FactSet, and the company cut full-year guidance.
$DaVita(DVA.US)$
– The healthcare provider saw shares surge 13.5% after the company beat earnings and revenue guidance for the first quarter, according to FactSet, and raised full-year earnings guidance. The company highlighted better volume trends and meaningful labor cost improvement as well as an improving macro environment.