Take a look at the companies making headlines in midday trading. Dollar General – Shares of Dollar General fell nearly 30% after the discount retailer slashed its full-year sales and profit guidance. Dollar General Chief Executive Todd Vasos said the weak sales trends were partly due to core customers feeling “financially strapped.” The retailer also reported disappointing fiscal second-quarter results. Shares of rival Dollar Tree fell more than 9% in sympathy. Confirmation – The buy now, pay later company’s stock surged 34% on stronger-than-expected fiscal first-quarter revenue outlook. Affirm expects revenue in the period to be between $640 million and $670 million, above the $625 million expected by analysts polled by LSEG. Best Buy — Shares rose 15%. Best Buy raised its profit forecast for the current fiscal year. The company currently expects adjusted earnings per share to range from $6.10 to $6.35. That’s up from the previous range of $5.75 to $6.20 per share. Second-quarter results also beat expectations. Nutanix — The cloud infrastructure company’s fourth-quarter profit and revenue beat estimates, sending the company’s stock soaring 20%. Nuatanix earned adjusted earnings of 27 cents per share on revenue of $548 million. Analysts expected earnings of 20 cents per share on revenue of $537 million, according to LSEG data. Shares of Okta – the secure identity cloud platform plunged about 16%. Okta’s revenue was $651 million, missing analysts’ consensus estimate of $679 million, according to StreetAccount. Bank of America downgraded Okta to underperform from buy due to the company’s financial results. Birkenstock – The sandal company fell 16%. Birkenstock reiterated full-year revenue guidance, predicting growth of about 19%. However, fiscal third-quarter adjusted earnings fell short of Wall Street expectations. Pure Storage — Shares of the data storage company plunged 13%. Pure Storage issued third-quarter operating income guidance that was below analysts’ expectations. Pure Storage expects operating income of $140 million in the current period, while analysts polled by FactSet estimated $148.1 million. NVIDIA — Shares of NVIDIA fell more than 3% even though the chip giant’s fiscal second-quarter performance beat Wall Street expectations. Nvidia reported adjusted earnings of 68 cents per share on revenue of $30.04 billion. Analysts polled by London Stock Exchange Group (LSEG) expected earnings of 64 cents per share on revenue of $28.7 billion. However, the artificial intelligence darling’s third-quarter revenue forecast fell short of investors’ lofty expectations. Veeva Systems – The cloud computing company beat Wall Street expectations for second-quarter profit and revenue, sending its shares up nearly 9%. Veeva reported adjusted earnings of $1.62 per share on revenue of $676.2 million. Analysts expected earnings of $1.53 per share on revenue of $667.8 million, according to FactSet. Crowdstrike – Shares of Crowdstrike rose 5% after the cybersecurity company reported stronger-than-expected earnings and revenue for its latest quarter. However, Crowdstrike lowered its full-year forecast following last month’s global outage. HP Inc. – Shares of HP rose more than 4%. Revenue in the fiscal third quarter was better than expected, at $13.52 billion, higher than the consensus estimate of $13.38 billion, according to LSEG. Adjusted earnings per share were 83 cents, below analysts’ forecasts of 86 cents per share. Victoria’s Secret – Shares of the lingerie company fell more than 1%. Although the company raised its full-year forecast, it still expects net sales to fall 1% annually. Early forecasts predicted a “low single-digit” decline, with analysts polled by London Stock Exchange Group (LSEG) estimating a 2.8% drop. —CNBC’s Samantha Subin, Yun Li, Pia Singh and Hakyung Kim contributed reporting.