What a week for markets. News of DeepSeek and potential tariffs ultimately sent most stocks to the downside to close the week. On DeepSeek, news of the Chinese A.I. platform's costs caused many technology stocks to sell off, including Nvidia's (NVDA) 17% slide on Monday. Four Mag 7 companies reported earnings to mixed results, with Apple (AAPL) closing lower and Tesla (TSLA) closing higher. Caroline Woods takes a closer look at the week's biggest movers.