WhyItDropped

S&P 500 · March 10, 2025

The March the tariffs kept changing

-2.70%

single-day change vs previous close

Part of a longer stretch

The 2025 tariff shock

midway through · 2025-02-19 → 2025-04-08, -18.90% over the whole period

What happened that day?

  • The S&P 500 fell 2.7% on the day
  • Tariff policy was changing every few days in this period — announced, deferred, applied in part, then revised
  • What the market disliked was less the tariffs than the chopping and changing. A high rate can still be calculated if it is fixed
  • Companies decide where to put factories and where to source parts on a horizon of years. When the rules change every few weeks, those decisions get postponed
  • Postponed decisions mean less investment, and less investment means lower growth. That is how tariffs affect the economy before any duty is collected
  • The decline ran to 8 April

Sources

Every figure on this page is recomputed from the original daily closing prices and checked against them at build time. The account of what happened is written from the sources listed above.