In keeping with my mechanical theme, since that's what I know, wild swings are a precursor to a total meltdown. Prior to catastrophic failure in a motor you will see wild fluctuations. Power will surge, then fall off, surge, fall off. Keep trying to run it...it and the system it runs will blow apart completely.
DOW will fall to 9000 today, hold and surge for awhile, fall catastrophically to below 8000 sooner than later.