How did NU's operating income surge in Q4 2024?

Nu Holdings Ltd. (NU) experienced a significant surge in operating income in Q4 2024, driven by several key factors: 1. **Revenue Growth**: Nu's revenue increased by 56% year-over-year, reaching $2.9 billion. This substantial growth was primarily driven by successful cross-sell and upsell efforts, leading to a 23% increase in the customer base to 109.7 million customers. 2. **Customer Engagement**: The company reported a robust monthly activity rate of 83.6%, up from 82.8% a year ago. This indicates a higher level of customer engagement and activity, which is a critical indicator of the company's ability to generate revenue from its customer base. 3. **Product Portfolio Expansion**: Nu's lending portfolio saw a 97% year-over-year growth, reaching $5.7 billion. This expansion into new product offerings, such as consumer finance and credit cards, has contributed significantly to the company's revenue and profitability. 4. **Efficiency Ratios**: The company's efficiency ratio improved by 60 basis points to 31.4%, reflecting better operational efficiency. This improvement in efficiency has likely contributed to the surge in net income, as it indicates a lower cost-to-serve ratio. 5. **International Expansion**: Nu's international expansion into Mexico and Colombia has been successful, with significant customer growth in these markets. This strategic move has not only increased the company's customer base but has also provided new revenue streams. In conclusion, Nu's operating income surge in Q4 2024 can be attributed to a combination of factors, including revenue growth, customer engagement, product portfolio expansion, efficiency ratios, and international expansion. These elements have collectively contributed to the company's strong financial performance during the period.