Senayepiyasasr aslznda bir bilmece gibi bir geydir. Diger hifbir ekonomik fmliyet sayzszz gazetede boylesine aynntzlz olamk apk[mmamzghr ve biqok insan tarafzndan b8ylesine ilgiyle izlenmmi$ir. Ote yondm bagka hifbir ekonomik faaliyet kendilerinigelecegin Bngciriisiine adamzg bir pk kkiden bu derece bqanlz olarak kendisini szyznp atlatamamzgtzr. Diger alanlara gorebirpay senedinin gelecekteki degerini saptamaya hwrlanmq uman szkzntzsz da yoktur. En iyi menkul kzymet analizcisinin ongririt raporu o kadar kotiZ olabilir kiyatznmczlar birpmfesyonelin tavsiyelerine uymak yerine onseziyle, batzl inmflayada herhmgi bir rassal s& reqle daha fazla getiri elde edebilirler. Benzer gekilde, biryatznmclnzngazetelerin ekonomi sayfalanna ok atarakpay senedi satzn almanzn igzltlendigi sdylenmi$tir, glnkii b6yle bir yo1 izlenmesi birpmfesyonel malistin apkp faydaszz dgzltlerine gore daha ucuzdur. Pay senedipiyasalarznzn geqekte 0ngdrUleme.z oldu@- nu vurgulaym bir y@n istatistiksel kmzt vardr. Diger bir defile, pay senedi fiyatlannzn izledigi yo1 temlde mssaldzr. Bu nedenlepay senedi fiyatlannzn izledikleri yola istatistikfiler mssalyzlrilyUg demktedir

The stock market is really something of an enigma No other economic activity is reported in such detail in so many newspapers and fallowed with such concern by so manypeople. Yet no activity seems to have been so successful in eluding many who devote themselves to predicting the future. There is no shortage of experts who areprepared to evaluate the future value one stock uersus that of another. It may be that the bestpmfessional securities analysist have a forecasting record so miserable that investors may do as well predicting earning by hunch, superstition or any random process as they would by following the advice of aprofessional. Similarly, it has been said that an investor is well advised to pick stocks by thmwing darts at the stock marketpage; since it is a cheaper to buy a set of darts than to obtain the apparently meless advice of a pmfessional analyst. There is a mass of statistical evidence that the behaviour of stock prices is in fact unpredictable. In other words, the behaviour of stock prices is essentially random Thepaths they follow are what staticians call random walks.