
kaaryakshamamaya athirthi

aadhunika portfolio sidhaanthathil, risk-ritten spektrathinte "kaaryakshamamaya" bhagangal ulkkollunna oru nikshepa portfoliyoyaanu kaaryakshamamaya athirthi (allengil portfolio athirthi). 
aupachaarikamaayi, uyarnna prathekshikkunna varumaanathodoppam mattoru portfolio nilavililla enna vyavastha thripthippeduthunna portfoliyokalude koottamaanu ithu, ennaal athe staanderd deviation oof ritten (athaayath.iii.apakadasaadhyatha). 
1952ll haari marcovits aanu kaaryakshamamaya athirthi aadyamaayi roopappeduthiyathu. 
marcovits model kaanuka.
avalokanam.
aasthikalude samyojanam, i.iii. oru portfoliyo, athinte apakadasaadhyathayude nilavaarathinu saadhyamaaya ettavum mikacha prathekshikkunna varumanam undengil (ithu portfoliyoyude varumaanathinte staanderd vyathiyaanam prathinidheekarikkunnu) "kaaryakshamamaayath" ennu vilikkunnu. ivide, apakadasaadyathayulla aasthikalude saadhyamaaya ellah samyojanavum risk-prathekshikkunna ritten spacil plott cheyyaan kazhiyum, saadhyamaaya ellah portfoliyokaludeyum shekharanam eee sthalathe oru pradeshathe nirvachikkunnu. apakadasaadhyathayillaatha oru swath kaivasham vaykkaanulla avasarathinte abhaavathil, eee mekhalayaanu avasarangal (saadhyamaaya settu). eee pradeshatthinte positteev charinja (mukalilekku charinja) mukalile athirthi oru hyperbolayude oru bhagamaanu, ithine "kaaryakshamamaya athirthi" ennu vilikkunnu. 
risk free asattum labhyamaanengil, avasara settu valuthaanu, athinte mukalile athirthi, kaaryakshamamaya athirthi, risk free asattinte varumaanathinte moolyathil lamba akshatthil ninnu purathuvarunna oru nerrekha vibhagamaanu, koodaathe risk free asattukalude maathram avasara settilekkulla sparsanamaanu. risk free asattum tanjansi portfolio thammilulla ellah portfoliyokalum risk free asattukalum tanjansi portfolio ulkkollunna portfoliyokalaanu, athesamayam tanjansi portfoliyoyude mukalilum valathuvashathumulla leanier athirthiyile ellah portfoliyokalum risk free nirakkil vaaypayeduthu tanjansi portfolioyilekku nikshepikkunnathiloodeya srishtikkunnathu.
chila swathukkalude prapanchangalil, vidagdhar kandethiyathu kaaryakshamamaya athirthi (marcovits model, kooduthal vishaalamaayi) model asthiratha polulla prashnangalkk vidheyamaanennu, udaaharanathinu, reference aasthikalkk uyarnna alavilulla parasparabandham undennaanu.

