Pork-chop of Doom: There are "electronic curbs" to prevent that happening, and if (for instance) the Dow moves down 7% in one session, the Market CLOSES for a period of time to prevent panic selling….
A 10,000 point drop would represent a great than 50% decline, so cannot happen….
If I am so lucky as to catch such an accidental plunge, I'd take FULL advantage of it with companies that pay high dividend yields like JNJ, MRK, HD, BGS because their stocks would collapse for the time being. But a 10,000 point plunge for the DJIA for even a few seconds would cause a circuit break and the market would stop trading for a few seconds all together so NOBODY would be allowed to place a quick trade unless you're a high frequency trade which you can place hundreds of trades within a matter of 1 second and you'd possibly squeak through for those 5 or so seconds before the circuit break happens.
Most of the inexperience investors would panic, those with experience will be taking advantage of some of the bargins out there
A great many people would have the opportunity to buy at bargain prices.
Panic, among some people.
which index are you taking about? Dow Industrials? Nasdaq? S&P 500?
people would start jumping out of windows