What do abrupt price fluctuations mean for a stock?

One example brought to the question is the case of the pharmaceutics company Mylan that completed the merger with a Pfizer division and Upjohn to form Viatris(VTRS) on November 15 approx.

What does a steep decline and recovery mean? That period variation was 2.10$-24.88$
-What has happened from Nov 10 to Nov 17?
-And why did it reach a higher than normal peak(24.88$)on Nov 13?