The stock market was unkind to NIELSEN HOLDINGS PLC in premarket trading MONDAY (3/21) after the company s Board of Directors rejected a $9 billion, $25.40/share takeover bid from an investment group led by ELLIOTT MANAGEMENT GROUP on SUNDAY (3/21). Shares dropped 17.55% in trading as of 8:15a (ET) to $20.15/share before the opening bell, blamed on the board s response to the offer, which said that another investment firm, WINDACRE PARTNERSHIP LLC, holder of 9.61% of NIELSEN plus an .