Stocks making the biggest moves premarket: Enbridge, Roku, GitLab and more
The Roku app is seen on a television in Hastings-on-Hudson, New York, July 25, 2023.

Check out the companies making headlines in premarket trading Wednesday.

Roku — The streaming stock jumped 12.5% after announcing plans to lay off 10% of its staff. Roku also lifted its third-quarter revenue guidance, saying it now expects revenue to range between $835 million and $875 million, versus prior guidance of $815 million. Along with the workforce reductions, Roku said it plans to consolidate office space and review its content slate to trim expenses.

Zscaler — The cloud security company lost 1.2% after reporting better-than-expected earnings in its fiscal fourth quarter and strong current-quarter guidance. Zscaler posted adjusted earnings of 64 cents per share while analysts polled by LSEG, formerly known as Refinitiv, expected 49 cents. Revenue also topped consensus by $25 million, coming in at $455 million. Additionally, the cybersecurity company said earnings and revenue should come in ahead of what analysts anticipate in the current quarter.

Enbridge , Dominion Energy — Enbridge shares lost 7.1% during premarket trading after Dominion, which is down 1.1%, said Tuesday it would sell its three natural gas distribution companies to the pipeline operator for $9.4 billion.

ResMed — Shares added 2% after Needham upgraded the medtech device company to buy from hold. ResMed, which makes CPAP devices for sleep apnea, is down 30% in the third quarter over concerns about the potential effect of weight-loss drugs on demand for its devices.

GitLab — Shares of the technology platform jumped 6.5% in premarket trading following a strong second-quarter report postmarket Tuesday. GitLab posted adjusted earnings of 1 cent per share on $140 million in revenue, while analysts polled by LSEG anticipated a loss of 3 cents per share and revenue of $130 million. The company's current-quarter revenue outlook beat analysts' expectations.

Toast — Shares of the restaurant tech stock added 3.8% after UBS upgraded shares to buy from neutral in a Wednesday note, citing improved potential for quarterly net new additions as well as margin expansion.

Asana — The work management stock fell 5.7% despite a strong report and outlook. Asana posted an adjusted loss of 4 cents per share on revenue of $162.5 million, while analysts polled by LSEG anticipated a loss of 11 cents per share on $158 million in revenue. It also raised its full-year guidance to an expected loss of 39 cents to 43 cents per share, lower than a previously expected loss of 50 cents to 55 cents per share.

Southwest Airlines — Shares of the Dallas-based carrier fell more than 4% after Southwest said August bookings were on the "lower-end" of expectations. Southwest expects third-quarter revenue per average seat mile to come in at the low end of its previous guidance, adding that fuel costs have risen.

C3.ai — The artificial intelligence software company rose 1.5% ahead of its earnings due after the close Wednesday. Analysts expect an adjusted loss of 12 cents per share on $73.8 million in revenue in the second quarter, and an adjusted loss of 4 cents per share on $78 million in revenue in the third quarter.

Novo Nordisk — Shares of the pharmaceutical giant gained 0.8% in premarket trading. The Danish company launched its Wegovy weight-loss drug in the U.K. on Monday, advancing the drug's rollout in Europe despite supply constraints.

AeroVironment — Shares of the unmanned aircraft systems maker rose 15.8% after AeroVironment beat analysts' expectations in its fiscal first quarter. AeroVironment posted adjusted earnings of $1 per share on revenue of $152 million, while analysts polled by LSEG called for earnings of 26 cents per share on revenue of $129 million.

— CNBC's Sam Subin, Michelle Fox Theobald and Jesse Pound contributed reporting.