Stocks making the biggest moves midday: Planet Fitness, Whirlpool, Vital Farms, Shake Shack & more

Check out the companies making the biggest moves midday: Planet Fitness — The gym operator fell nearly 33% after it lowered its full-year earnings outlook. The company now sees its bottom line growing about 4% year on year. That's down from a forecast that called for an expansion of 9%-10%. Vital Farms — The eggs producer dropped 20% on a surprise loss for the first quarter. Vital Farms lost 3 cents per share, excluding certain items. Analysts polled by FactSet expected a profit of 6 cents per share. The company also cut its full-year earnings outlook. Datadog — Shares are up by 28% after the software company beat Q1 expectations. The company reported earnings per share of 61 cents, which exceeded FactSet's consensus of 51 cents per share. Their Q2 revenue guidance sits between $1.07 to $1.08 billion, which is above FactSet's $993.9 million. AAON — The Oklahoma-based air conditioning and heating equipment manufacturer soared 40% after first-quarter earnings, EBITDA and revenue all topped Wall Street analysts' estimates, according to FactSet, and AAON raised its full-year revenue guidance by as much as 45%. Shake Shack — Shares tumbled 29% after the burger chain's first-quarter results fell short of expectations and it reported an operating loss of $2.6 million. Shake Shack's earnings per share broke even, versus earnings of 12 cents a share expected from analysts polled by LSEG. Revenue came in at $366.7 million, versus the $372 million consensus estimate. …