Why Is the Stock Market Up or Down Today? - SPY Explained

SPY (SPDR S&P 500 ETF) is the most-traded proxy for the US stock market. When people ask "why is the market up today?" or "why did stocks crash?", SPY is the answer. Use ExplainThisMove to get a real-time explanation for any SPY move - macro drivers, earnings impact, and Fed context included.

What moves the S&P 500?

• Federal Reserve policy: FOMC rate decisions and Fed chair statements are the single biggest market movers. Rate cut signals drive rallies; hawkish surprises trigger selloffs.
• Inflation data: CPI and PCE prints that come in hotter or cooler than expected cause immediate SPY reactions as they shift rate cut expectations.
• Jobs reports: The monthly Non-Farm Payrolls report is a major macro catalyst - strong jobs = fewer rate cuts = sometimes negative for stocks.
• Mega-cap earnings: The top 10 S&P 500 components (AAPL, MSFT, NVDA, AMZN, META, GOOGL, TSLA) make up ~35% of the index. Earnings from these names move SPY directly.
• Treasury yields: Rising 10-year yields increase the discount rate on future earnings, compressing valuations - particularly for growth stocks that dominate the index.
• Geopolitical events: Trade policy, tariff announcements, and geopolitical tensions (especially affecting supply chains) cause broad market moves.

Use ExplainThisMove to get a real-time explanation for any SPY move. Also explore: QQQ, NVDA, AAPL.