This dissertation deals with the links between stock market returns and foreign exchange rates, industrial production and exports to Germany in three Central and East European countries (the Czech Republic, Hungary and Poland). The main questions addressed are: "Do macroeconomic factors related to foreign exchange rates and industrial production affect stock market returns in the Visegrad-3? And what is the impact of exports to Germany on those stock returns?" This analysis makes use of panel-data and the Arbitrage Pricing Theory (APT) to produce results. Firstly, foreign exchange rates are found to have a negative effect on stock returns. However the divergence in currency returns between the three countries means that the overall effect may be due to some factors that are not accounted for in this analysis. Secondly, there is a positive, but lagged, association between industrial production and stock returns. Thirdly, exports to Germany from the region are also found to have a positive impact on the stock returns of the Visegrad-3. Finally, there is divergence among the three countries with respect to the relationship between the macroeconomic factors and stock returns. Poland and Hungary are seen to exert a significant amount of influence over the region's stock markets.

The study investigates whether the main capital market theories and pricing models provide a reasonably accurate description of the working and efficiency of capital markets, of the pricing of shares and options and the effect the risk/return relationship has on investor behaviour. The capital market theories and pricing models included in the study are Portfolio Theory, the Efficient Market Hypothesis (EMH), the Capital Asset Pricing Model (CAPM), the Arbitrage Pricing Theory (APT), Options Theory and the BlackScholes (8-S) Option Pricing Model. The main conclusion of the study is that the main capital market theories and pricing models, as reviewed in the study, do provide a reasonably accurate description of reality, but a number of anomalies and controversial issues still need to be resolved. The main recommendation of the study is that research into these theories and models should continue unabated, while the specific recommendations in a South African context are the following: ( 1) the benefits of global diversification for South African investors should continue to be investigated; (2) the level and degree of efficiency of the JSE Securities Exchange SA (JSE) should continue to be monitored, and it should be established whether alternative theories to the EMH provide complementary or better descriptions of the efficiency of the South African market; (3) both the CAPM and the APT should continue to be tested, both individually and jointly, in order to better understand the pricing mechanism of, and risk/return relationship on the JSE; (4) much South African research still needs to be conducted on the efficiency of the relatively new options market and the application of the B-S Option Pricing Model under South African conditions. / Financial Accounting / M. Com. (Accounting)

The study investigates whether the main capital market theories and pricing models provide a reasonably accurate description of the working and efficiency of capital markets, of the pricing of shares and options and the effect the risk/return relationship has on investor behaviour. The capital market theories and pricing models included in the study are Portfolio Theory, the Efficient Market Hypothesis (EMH), the Capital Asset Pricing Model (CAPM), the Arbitrage Pricing Theory (APT), Options Theory and the BlackScholes (8-S) Option Pricing Model. The main conclusion of the study is that the main capital market theories and pricing models, as reviewed in the study, do provide a reasonably accurate description of reality, but a number of anomalies and controversial issues still need to be resolved. The main recommendation of the study is that research into these theories and models should continue unabated, while the specific recommendations in a South African context are the following: ( 1) the benefits of global diversification for South African investors should continue to be investigated; (2) the level and degree of efficiency of the JSE Securities Exchange SA (JSE) should continue to be monitored, and it should be established whether alternative theories to the EMH provide complementary or better descriptions of the efficiency of the South African market; (3) both the CAPM and the APT should continue to be tested, both individually and jointly, in order to better understand the pricing mechanism of, and risk/return relationship on the JSE; (4) much South African research still needs to be conducted on the efficiency of the relatively new options market and the application of the B-S Option Pricing Model under South African conditions. / Financial Accounting / M. Com. (Accounting)

Cette thèse traite plusieurs problèmes qui se posent pour les marchés financiers avec coûts de transaction et se compose de quatre parties.On commence, dans la première partie, par une étude du problème de couverture approximative d’une option Européenne pour des marchés de volatilité locale avec coûts de transaction proportionnelles.Dans la seconde partie, on considère le problème de l’optimisation de consommation dans le modèle de Kabanov, lorsque les prix sont conduits par un processus de Lévy.Dans la troisième partie, on propose un modèle général incluant le cas de coûts fixes et coûts proportionnels. En introduisant la notion de fonction liquidative, on étudie le problème de sur-réplication d’une option et plusieurs types d’opportunités d’arbitrage.La dernière partie est consacrée à l’étude du problème de maximisation de l’utilité de la richesse terminale d’une portefeuille sous contraintes de risque. / This thesis deals with different problems related to markets with transaction costs and is composed of four parts.In part I, we begin with the study of assymptotic hedging a European option in a local volatility model with bid-ask spread.In part II, we study the optimal consumption problem in a Kabanov model with jumps and with default risk allowed.In part III, we sugest a general market model defined by a liquidation procès. This model is more general than the models with both fixed and proportional transaction costs. We study the problem of super-hedging an option, and the arbitrage theory in this model.In the last part, we study the utility maximization problem under expected risk constraint.

Die studie vergelyk die prestasie van 'n koop-en-hou-strategie met die van 'n tydsberekeningstrategie binne die raamwerk van die arbitrasie-prysbepalingsteorie (APT) op die nywerheidsindeks van die Johannesburgse Aandelebeurs (JA). Die periode van die studie is oor twee tydperke, naamlik Januarie 1970 tot September 1987 en Januarie 1989 tot Junie 1997. Die langtermyntendens van die nywerheidsindeks en APT-faktore is bepaal deur die beste nie-reglynige model vir elke tydreeks te vind. Reglynige meervoudige stapsgewyse regressie-ontleding is gebruik om die bewegings van die nywerheidsindeks rondom die langtermyntendens te voorspel. Die sloeringsreekse van die langtermyntendensresidutelling van die APT-faktore en die sloeringsreekse van die eerste-ordeverskiltelling van die langtermyntendensresidutelling is as moontlike voorspellers gebruik. Gegrond hierop is beslissingslyne ontwik:kel wat gebruik is vir die implementering van 'n tydsberekeningstrategie. Die resultate van die studie is die volgende: • Waar die sloeringsreekse van die langtermyntendensresidutelling van die APTfaktore as moontlike voorspellers gebruik is, is die risiko-aangepaste opbrengskoers van 'n tydsberekeningstrategie 6, 41 persent en 0, 71 persent b6 die van 'n koop-en-hou-strategie vir tydperk een en twee onderskeidelik. • Waar die sloeringsreekse van die eerste-ordeverskiltelling van die langtermyntendensresidutelling van die APT-faktore as moontlike voorspellers gebruik is, is die risiko-aangepaste opbrengskoers van 'n tydsberekeningstrategie 10,40 persent en 1,04 persent b6 die van 'n koop-enhou- strategie vir tydperk een en twee onderskeidelik. Die belangrikste gevolgtrekking van die studie is dat die APT en 'n tydsberekeningstrategie teoreties en prakties versoenbaar is op die JA. Aanbevelings vir toekomstige navorsing is die volgende: ( 1) sistematiese risikofaktore, anders as makro-ekonomiese faktore, behoort identifiseer te word wat die voorspellingswaarde van die faktore in die tweede tydperk van die studie kan verhoog; (2) elke stap van die model wat ontwikkel is, behoort op elke indeks van die JA toegepas te word om die risiko-aangepaste opbrengskoers van 'n tydsberekeningstrategie toegepas op elkeen van die indekse met die van 'n koop-en-hou-strategie te vergelyk; en (3) die invloed van transaksiekoste en dividende op die potensiele voordele van tydsberekening moet bepaal word. / The study compares the performance of a buy-and-hold strategy with that of a markettiming strategy in the framework of the arbitrage pricing theory (APT) applied to the industrial index of the Johannesburg Stock Exchange (JSE). The study period is divided into two parts, namely January 1970 to September 1987 and January 1989 to June 1997. The long-term trend of the industrial index and every APT factor is determined by finding the best nonlinear model for each time series. Linear multiple stepwise regression analysis, with the lagged time series of the long-term trend error terms of the APT factors, is used to forecast the movement of the industrial index around its long-term trend. Decision lines were developed to implement a market-timing strategy. The results of the study are as follows: • Where the lagged time series of the long-term trend error terms of the APT factors were used as possible predictors, the risk-adjusted return of a markettiming strategy was 6, 41 percent and 0, 71 percent higher than that of a buyand- hold strategy for periods one and two respectively. • Where the lagged time series of the first-order difference of the long-term trend error term of the APT factors were used as possible predictors, the riskadjusted return of the market-timing strategy was 10,40 percent and 1,04 percent higher than that of a buy-and-hold strategy for periods one and two respectively. The main conclusion of the study is that the APT and a market-timing strategy are theoretically and practically reconcilable on the JSE. The main recommendations of the study are the following: (1) systematic risk factors, other than macroeconomic factors, should be identified in order to increase the forecasting value of these factors in the second period of the study; (2) each step of the model developed in this study should be repeated on every index of the JSE; and (3) the influence of transaction costs and dividends on the potential benefits of a market-timing strategy should be determined. / Business Management / DCom (Sakebestuur)

The impact of political and economic events on the asset pricing model described by the arbitrage pricing theory (APTM) was examined in order to establish if they had caused any changes in its specification. It was concluded that the APTM is not stationary and that it must be continuously tested before it can be used as political and economic events can change its specification. It was also found that political events had a more direct effect on the specification of the APTM, in that their effect is more immediate, than did economic events, which influenced the APTM by first influencing the economic environment in which it operated. The conventional approach that would have evaluated important political and economic events, case by case, to determine whether they affected the linear factor model (LFM), and subsequently the APTM, could not be used since no correlation was found between the pricing of a risk factor in the LFM and its subsequent pricing in the APTM. A new approach was then followed in which a correlation with a political or economic event was sought whenever a change was detected in the specification of the APTM. This was achieved by first finding the best subset LFM, chosen for producing the highest adjusted R2 , month by month, over 87 periods from 20 October1991 to 21 June 1998, using a combination of nine prespecified risk factors (five of which were proxies for economic events and one for political events). Multivariate analysis techniques were then used to establish which risk factors were priced most often during the three equal subperiods into which the 87 periods were broken up. Using the above methodology, the researcher was able to conclude that political events changed the specification of the APTM in late 1991. After the national elections in April 1994 it was found that the acceptance of South Africa into the world economic community had again changed the specification of the APTM and the two most important factors were proxies for economic events. / Business Leadership / DBL

Die studie vergelyk die prestasie van 'n koop-en-hou-strategie met die van 'n tydsberekeningstrategie binne die raamwerk van die arbitrasie-prysbepalingsteorie (APT) op die nywerheidsindeks van die Johannesburgse Aandelebeurs (JA). Die periode van die studie is oor twee tydperke, naamlik Januarie 1970 tot September 1987 en Januarie 1989 tot Junie 1997. Die langtermyntendens van die nywerheidsindeks en APT-faktore is bepaal deur die beste nie-reglynige model vir elke tydreeks te vind. Reglynige meervoudige stapsgewyse regressie-ontleding is gebruik om die bewegings van die nywerheidsindeks rondom die langtermyntendens te voorspel. Die sloeringsreekse van die langtermyntendensresidutelling van die APT-faktore en die sloeringsreekse van die eerste-ordeverskiltelling van die langtermyntendensresidutelling is as moontlike voorspellers gebruik. Gegrond hierop is beslissingslyne ontwik:kel wat gebruik is vir die implementering van 'n tydsberekeningstrategie. Die resultate van die studie is die volgende: • Waar die sloeringsreekse van die langtermyntendensresidutelling van die APTfaktore as moontlike voorspellers gebruik is, is die risiko-aangepaste opbrengskoers van 'n tydsberekeningstrategie 6, 41 persent en 0, 71 persent b6 die van 'n koop-en-hou-strategie vir tydperk een en twee onderskeidelik. • Waar die sloeringsreekse van die eerste-ordeverskiltelling van die langtermyntendensresidutelling van die APT-faktore as moontlike voorspellers gebruik is, is die risiko-aangepaste opbrengskoers van 'n tydsberekeningstrategie 10,40 persent en 1,04 persent b6 die van 'n koop-enhou- strategie vir tydperk een en twee onderskeidelik. Die belangrikste gevolgtrekking van die studie is dat die APT en 'n tydsberekeningstrategie teoreties en prakties versoenbaar is op die JA. Aanbevelings vir toekomstige navorsing is die volgende: ( 1) sistematiese risikofaktore, anders as makro-ekonomiese faktore, behoort identifiseer te word wat die voorspellingswaarde van die faktore in die tweede tydperk van die studie kan verhoog; (2) elke stap van die model wat ontwikkel is, behoort op elke indeks van die JA toegepas te word om die risiko-aangepaste opbrengskoers van 'n tydsberekeningstrategie toegepas op elkeen van die indekse met die van 'n koop-en-hou-strategie te vergelyk; en (3) die invloed van transaksiekoste en dividende op die potensiele voordele van tydsberekening moet bepaal word. / The study compares the performance of a buy-and-hold strategy with that of a markettiming strategy in the framework of the arbitrage pricing theory (APT) applied to the industrial index of the Johannesburg Stock Exchange (JSE). The study period is divided into two parts, namely January 1970 to September 1987 and January 1989 to June 1997. The long-term trend of the industrial index and every APT factor is determined by finding the best nonlinear model for each time series. Linear multiple stepwise regression analysis, with the lagged time series of the long-term trend error terms of the APT factors, is used to forecast the movement of the industrial index around its long-term trend. Decision lines were developed to implement a market-timing strategy. The results of the study are as follows: • Where the lagged time series of the long-term trend error terms of the APT factors were used as possible predictors, the risk-adjusted return of a markettiming strategy was 6, 41 percent and 0, 71 percent higher than that of a buyand- hold strategy for periods one and two respectively. • Where the lagged time series of the first-order difference of the long-term trend error term of the APT factors were used as possible predictors, the riskadjusted return of the market-timing strategy was 10,40 percent and 1,04 percent higher than that of a buy-and-hold strategy for periods one and two respectively. The main conclusion of the study is that the APT and a market-timing strategy are theoretically and practically reconcilable on the JSE. The main recommendations of the study are the following: (1) systematic risk factors, other than macroeconomic factors, should be identified in order to increase the forecasting value of these factors in the second period of the study; (2) each step of the model developed in this study should be repeated on every index of the JSE; and (3) the influence of transaction costs and dividends on the potential benefits of a market-timing strategy should be determined. / Business Management / DCom (Sakebestuur)

The impact of political and economic events on the asset pricing model described by the arbitrage pricing theory (APTM) was examined in order to establish if they had caused any changes in its specification. It was concluded that the APTM is not stationary and that it must be continuously tested before it can be used as political and economic events can change its specification. It was also found that political events had a more direct effect on the specification of the APTM, in that their effect is more immediate, than did economic events, which influenced the APTM by first influencing the economic environment in which it operated. The conventional approach that would have evaluated important political and economic events, case by case, to determine whether they affected the linear factor model (LFM), and subsequently the APTM, could not be used since no correlation was found between the pricing of a risk factor in the LFM and its subsequent pricing in the APTM. A new approach was then followed in which a correlation with a political or economic event was sought whenever a change was detected in the specification of the APTM. This was achieved by first finding the best subset LFM, chosen for producing the highest adjusted R2 , month by month, over 87 periods from 20 October1991 to 21 June 1998, using a combination of nine prespecified risk factors (five of which were proxies for economic events and one for political events). Multivariate analysis techniques were then used to establish which risk factors were priced most often during the three equal subperiods into which the 87 periods were broken up. Using the above methodology, the researcher was able to conclude that political events changed the specification of the APTM in late 1991. After the national elections in April 1994 it was found that the acceptance of South Africa into the world economic community had again changed the specification of the APTM and the two most important factors were proxies for economic events. / Business Leadership / DBL

Investors constantly seek information that provides an edge over the market. One of the conventional methods is to find factors which can predict asset returns. In this study we improve the Fama and French Five-Factor model with Regime-Switches, student's t distributions and copula dependencies. We also add price momentum as a sixth factor and add a one-day lag to the factors. The Regime-Switches are obtained from a Hidden Markov Model with conditional Student's t distributions. For the return process we use factor data as input, Student's t distributed residuals, and Student's t copula dependencies. To fit the copulas, we develop a novel approach based on the Expectation-Maximisation algorithm. The results are promising as the quantiles for most of the portfolios show a good fit to the theoretical quantiles. Using a sophisticated Stochastic Programming model, we back-test the predictive power over a 26 year period out-of-sample. Furthermore we analyse the performance of different factors during different market regimes.