SOXL plunges 19%, Claude Code backdoor report, and the NaN loss-spike question

Chip stocks got crushed, a reported supply-chain attack hit a flagship AI coding tool, and we walk through one of the toughest debugging questions in senior ML interviews. Markets: SOXL down 19.47% to $82.45, QQQ down 2.49% to $697.53, VGT down 3.23% to $118.29, VUG down 2.17% to $85.79. AI news: Security researchers report that Anthropic's official Claude Code extensions were backdoored to push a remote-access trojan to developer laptops. The report is not yet confirmed. Watch for Anthropic's disclosure, the affected versions, remediation steps, and any changes to IPO risk factors. Interview Tip of the Day: Your large transformer's training loss suddenly spikes to NaN at step 40,000. How do you diagnose it, and how do you resume without repeating the spike? Did You Know: Why the original Space Invaders sped up as you destroyed aliens. Questions or feedback: [email protected]