[pt] O Bitcoin surgiu no fim da década passada. Desde então, emergiu uma nova classe de ativos: as criptomoedas. O ecossistema das moedas digitais vem avançando a passos largos, seja pelo surgimento de novas moedas, pelo nível de capitalização, pela escalada de investidores ou pelo expressivo desempenho em 2017. Dado o quadro, as criptomoedas se consolidam a cada dia como uma alternativa de investimento, tornando-se de vez uma rota do mercado financeiro. Por consequência, surge a necessidade de avaliar e estimar medidas de risco para esses ativos. Este estudo estimou os coeficientes Beta das quatorze maiores criptomoedas da economia – de acordo com o nível de capitalização – em relação à índices teóricos, com o fito de auxiliar os gestores de portfólios no apreçamento e na formatação de estratégias. Através de uma regressão de retornos passados destas moedas sobre os retornos dos índices de criptoativos, de ações e de uma cesta de moedas contra o dólar americano, estimou-se o Beta dos ativos. A partir das análises, concluiu-se que o Bitcoin possui elevada sensibilidade aos índices de criptomoedas, mesma condicionante para o Ethereum, porém com correlação mais branda aos referenciais, bem como ao próprio Bitcoin. Quantos às demais moedas, estas não exprimiram fator de risco associado aos índices de criptomoedas, visto os baixos coeficientes. Quando analisados os criptoativos em relação aos índices acionários e de moedas contra o dólar, constatou-se que os coeficientes foram iguais a zero. Portanto, o desempenho das criptomoedas, na janela de tempo estudada, possui relação involuntária às oscilações destes índices. / [en] Bitcoin has risen at the end of the last decade. Since then, a new class of assets emerged: the cryptocurrencies. The cryptocurrencies scenario has been advancing rapidly, by the emergence of new currencies, by the level of capitalization, either by the increase of investors or by its significant performance in 2017. Given the situation, cryptocurrencies keep consolidating itself every day as an investment alternative, becoming a permanent route for the financial market. Consequently, it becomes necessary to estimate risk measures for these assets. This study estimated the Beta coefficients of the largest cryptocurrencies – according to its capitalization level – in relation to theoretical indexes, in order to assist portfolios managers in pricing. Through a regression of past returns of virtual currencies on the returns of the cryptocurrencies indexes, stocks and a portfolio of currencies against the US dollar, the digital assets beta was estimated. From these analyses, it was possible to conclude that Bitcoin is significantly sensitive to cryptocurrencies indexes, the same condition for Ethereum, but with a softer correlation to the references, as well as Bitcoin itself. With respect to the other currencies, they did not express a relevant risk factor associated with cryptocurrencies indexes, due to low coefficient values. When analyzing the cryptocurrency in relation to the stock and currency indexes against the US dollar, it was noted that the coefficients were zero. Therefore, the digital currencies performance of this study, in the given timeframe, has an involuntary relation to the fluctuations of those indexes.

The principal objective of this work is to test the efficiency of the U.S. capital market and to specify the degree of this effectiveness and then to find out the optimal strategy to evaluate the money invested into selected companies. At first there is theory description - the basic classification of securities, explication of the notion of efficiency of capital market, the methods of test the efficiency, several statistic indicators of the capital market like return average, standard deviation or coefficients of the capital market. Following this theoretical base there is create an analyse of one of the most popular capital markets in American index S&P 500 and of its sectors and some securities. Historical dates of years 2003 - 2008 are analysed and on the basis of results there are propositions which strategy to choose. There wasn't directly confirmed effectiveness of U.S. capital market in this work. So there was a possibility to choose an investment strategy to get an above-average return. The results were very influenced by the crisis since 2007.

The work is focussed on the determination of capital structure in its market values, determination of the cost of non-own capital, and determination of the cost of equity, primarily by using the CAPM method. In terms of the CAPM procedure the work deals with the main parameters required by the method, such as risk-free yield rate, risk market premium, and beta coefficient. Furthermore, attention is given to modifications resulting from the inaccuracies of the CAPM method to make the method correspond as much as possible with the actual yield and risk of shares historically achieved at the capital market, and likewise to modifications needed when applying the CAPM method to the valuation of Czech businesses. The recommended procedure of determining the market discount rate for the valuation of an enterprise is applied on an example. Data obtained from the capital market of the Czech Republic are used to calculate the risk premium of the Czech capital market and beta coefficient of selected ten shares out of the Czech capital market, giving an assessment of the possibility of using the data obtained from the Czech capital market for the valuation of businesses incorporated in the Czech Republic.