How a more-focused growth index can cut your risk in the stock market - MarketWatch
1. Nvidia shares fell 17% after DeepSeek's AI tech announcement. 2. Investors fear slowing growth in Nvidia's AI-hardware sector. 3. S&P 500 concentration risk remains high with 'Magnificent Seven'. 4. Nvidia comprises 11.9% of S&P 500 Growth ETF's portfolio. 5. Investors may consider equal-weighted and diversified indexes.