The recent drop is not very significant (a little over 10%).
The Great Financial Crisis caused a 60% drop around 2008/2009.
https://www.nytimes.com/2020/02/27/business/what-is-a-stock-...
https://www.nytimes.com/2020/02/27/business/what-is-a-stock-...
Bonds are indicators of expectations and risks in the near-to-long future. When their rates get strange, people worry.
GFC didn't happen over 1 week, the bear market from GFC was from October 9/10, 2007 to March 9, 2009.