An eye opener for those who buy/sell based on number of buyers/sellers
"Quote stuffing" a focus in flash crash probe
http://www.reuters.com/article/2010/09/02/us-sec-trades-idUSTRE6812ZS20100902
"Quote stuffing" a focus in flash crash probe
http://www.reuters.com/article/2010/09/02/us-sec-trades-idUSTRE6812ZS20100902
Investors could make trades under the false impression that those orders were legitimate, only to see liquidity disappear and the market move against them when the orders are canceled -- all in the blink of an eye.