WhyItDropped

S&P 500 · May 20, 2010

After Germany banned short selling

-3.90%

single-day change vs previous close

Part of a longer stretch

Europe's crisis and the flash crash

midway through · 2010-04-23 → 2010-07-02, -15.99% over the whole period

What happened that day?

  • On 20 May 2010 the S&P 500 fell 3.9%
  • Two days earlier Germany had banned short selling of certain financial instruments without warning
  • Such a ban blocks bets that prices will fall. It usually appears when things are serious
  • That it was announced alone, without coordination, deepened the alarm — Europe could not move together
  • The gains from the rescue fund agreement disappeared within ten days
  • Trying to hold up a price by regulation often reads as evidence that something worse is underneath
  • In this stretch the index was 15.99% below its peak

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.