the companies making the headlines in after-hours trading. Gap - Shares rose 15% in the aftermarket after the retailer's earnings report showed a massive improvement in margins. Revenue came narrowly below expectations at $3.28 billion, with analysts surveyed by Refinitiv expecting $3.29 billion. Shares fell 0.2% after the retailer said it missed revenue, posting $53.65 billion for the fiscal third quarter, according to Costco - Refinitiv, with analysts predicting $54.57 billion. Costco saw $3.43 in adjusted earnings per share, above the $3.29 analysts had predicted. Ulta Beauty - Shares of Ulta fell 8% in long-term trading after the cosmetics retailer reaffirmed its guidance for full-year earnings and comparable sales. Ulta slightly raised its revenue outlook for the year. The company reported earnings per share of $6.88 on revenue of $2.63 billion. Analysts are calling for earnings of $6.87 per share and revenue of $2.62 billion, according to Refinitiv. Workday — Cloud stock rose 7% hours later after a strong earnings report and the announcement of a new chief financial officer. Workday reports adjusted earnings per share of $1.31, while analysts polled by Refinitiv estimated $1.12. The company also narrowly beat revenue expectations of $1.68 billion against a $1.67 billion estimate. Workday also announced that Zane Rowe, most recently VMware's chief financial officer, will become chief financial officer from next month. Marvell Technology — Stocks were up 14% in post-bell trading after the semiconductor maker beat analysts' expectations for the first quarter. Analysts polled by Refinitiv estimated revenue of 29 cents per share and $1.3 billion, while Marvell recorded 31 cents per share adjusted earnings on revenue of $1.32 billion. The company also said revenue growth should accelerate in the second half of the fiscal year. RH — Luxury retailer RH fell 3% after hours as weak guidance for the current quarter drew attention to strong first-quarter earnings. According to Refinitiv, the company said it expects revenues of between $765 million and $775 million this quarter, below Street's forecast of $784 million. Still, RH surpassed analysts' expectations for revenue of $739 million in the first quarter, compared to $727 million. — CNBC's Darla Mercado contributed reporting.