about 5 major funds own about 40%  of   Iamgold ....they can do plenty of things with the stock price with different trading strategies when you hold these amount of shares considering there is about 370 million shares outstanding and they hold 125 million shares

this reminds me of Agnico EAGLE ...they had the same mining  problems    .stock gropped to 31.00 and got pummeled for three days ..   now its 47

 

guess who major holders are

Blackrock        yes  .... as of Dec 31st 2012  they owned 51 million shares

Van Eck Associates   has a ton

between these two they practically control the  stock prices of many companies 

and the rest is in Gld vectors Etf

and two others i cant remember off the top of my head