▁dropped ▁ 4 4 5 ▁points ▁in ▁the ▁last ▁minutes ▁of ▁the ▁trad ing ▁session , ▁closing ▁at ▁ 7 , 5 5 2 , ▁the ▁lowest ▁point ▁in ▁six ▁years . ▁Sh ares ▁in ▁Cit igr oup ▁pl um met ed ▁another ▁ 2 6 %, ▁and ▁shares ▁of ▁other ▁major ▁US ▁financial ▁institutions ▁dropped ▁by ▁more ▁than ▁ 1 0 %. ▁ ▁On ▁Friday , ▁November ▁ 2 1 ▁the ▁Dow ▁Jones ▁Indust rial ▁A verage ▁recovered ▁about ▁half ▁of ▁the ▁loss ▁for ▁the ▁week ▁and ▁closed ▁above ▁ 8 , 0 0 0 ; ▁however , ▁stock s ▁of ▁Cit ib ank , ▁Bank ▁of ▁America , ▁and ▁J . P . ▁Morgan ▁Ch ase ▁continued ▁to ▁decl ine . ▁It ▁was ▁unclear ▁whether ▁the ▁drop ▁in ▁the ▁value ▁of ▁Cit igr oup ▁stock ▁to ▁under ▁$ 4 ▁reflected ▁financial ▁weak ness ▁of ▁the ▁bank ▁or ▁what ▁rescue ▁plan ▁could ▁be ▁craft ed . ▁One ▁theory ▁for ▁the ▁disappoint ment ▁of ▁invest ors ▁was ▁that ▁the ▁failure ▁of ▁the ▁Tre as ury ▁to ▁purchase ▁to xic ▁mort g age ▁related ▁se cur ities ▁held ▁by ▁the ▁bank ▁left ▁bill ions ▁of ▁un real ized ▁losses ▁on ▁the ▁books . ▁Cit igr oup ▁continues ▁to ▁hold ▁$ 2 0 ▁billion ▁in ▁mort g age - related ▁se cur ities , ▁currently ▁val ued ▁at ▁a ▁substantial ▁disc ount . ▁ ▁As ▁of ▁the ▁week ▁of ▁November ▁ 1 6 ▁stock ▁losses ▁in ▁United ▁States ▁mark ets ▁during ▁ 2 0 0