Check out the companies making headlines in midday trading. Dollar General – The discount retailer’s shares tumbled nearly 30% after the company slashed its sales and profit guidance for the full year. Dollar General CEO Todd Vasos said the softer sales trends are partially attributable to a core customer who feels “financially constrained.” The retailer also reported disappointing results for the fiscal second quarter. Shares of competitor Dollar Tree fell more than 9% in sympathy. Affirm – Shares surged 34% on the buy now, pay later company’s stronger-than-expected revenue outlook for the fiscal first quarter. Affirm expects revenue for the period to come in between $640 million and $670 million, above the $625 million expected from analysts surveyed by LSEG. Best Buy – Shares jumped 15%. Best Buy raised its earnings outlook for the fiscal year. The company now expects an adjusted earnings range of $6.10 to $6.35 per share. That’s higher than the prior range of between $5.75 and $6.20 per share. Results for the fiscal second-quarter were also better than expected. Nutanix – The stock surged 20% following the cloud infrastructure company’s earnings and revenue beat for the fiscal fourth quarter. Nuatanix earned an adjusted 27 cents per share on $548 million in revenue. Analysts were expecting earnings of 20 cents per share on revenue of $537 million, per LSEG. Okta – Shares of the secure identity cloud platform plunged about 16%. Okta’s billings came in at $651 million, lower than analysts’ consensus estimate of $679 million, according to StreetAccount. Bank of America double downgraded the stock to underperform from buy on the back of Okta’s financial results. Birkenstock – The sandal company fell 16%. Birkenstock reaffirmed its full-year revenue guidance, anticipating growth of about 19%. Fiscal third-quarter adjusted earnings came in below the Street’s expectations, however. Pure Storage – Shares of the data storage company plunged 13%. Pure Storage issued third-quarter operating income guidance that was below analysts’ estimates. For the current period, Pure Storage expects operating income to come in at $140 million, while analysts polled by FactSet estimated $148.1 million. Nvidia – Shares slid more than 3% despite the chip giant beating the Street’s expectations for the fiscal second quarter . Nvidia reported adjusted earnings of 68 cents per share on $30.04 billion in revenue. Analysts surveyed by LSEG expected 64 cents per share on revenue of $28.7 billion. The AI darling’s revenue forecast for the third quarter, however, came up short of investors’ lofty expectations. Veeva Systems – The cloud computing company moved nearly 9% higher after its fiscal second-quarter earnings and revenue surpassed the Street’s expectations. Veeva reported adjusted earnings of $1.62 per share on $676.2 million in revenue. Analysts were expecting $1.53 per share on revenue of $667.8 million, according to FactSet. Crowdstrike – Shares popped 5% after the cybersecurity company posted stronger-than-expected earnings and revenue for the recent quarter. Crowdstrike, however, lowered its full-year outlook on the heels of last month’s global outage. HP Inc. – HP’s shares advanced more than 4%. Revenue for the fiscal third quarter came in better than expected at $13.52 billion, above the consensus estimate of $13.38 billion, per LSEG. Adjusted earnings of 83 cents per share missed the mark, as analysts called for 86 cents per share. Victoria’s Secret – Shares of the lingerie company slipped more than 1%. Although the company raised its full-year outlook, it still anticipates a 1% year-over-year decline in net sales. An earlier forecast predicted a ” low single-digit ” decline, and analysts surveyed by LSEG estimated a 2.8% pullback. — CNBC’s Samantha Subin, Yun Li, Pia Singh and Hakyung Kim contributed reporting.