Return and Volatility spillovers among stock and Foreign Exchange Markets: Empirical Evidence from selected African Markets

Return and volatility dynamics in financial markets across the world have recently become important for the purpose of asset pricing, portfolio allocation and risk management. However, volatility, which come about as a result of the actions of market participants can help adapt to different situations and perform when it really matters. With recent development and liberalization among financial markets in emerging and frontier markets, the need for how the equity and foreign exchange markets interact and the extent to which return and volatility spillover are spread across countries is of importance to investors and policy makers at large. Financial markets in Africa have received attention leading to investors diversifying into them in times of crisis and contagion effects in developed countries. Regardless of the benefits these markets may offer, investors must be wary of issues such as thin trading, volatility that exists in the equity and currency markets and its related fluctuations. The study employs a VAR-GARCH BEKK model to study the return and volatility dynamics between the stock and foreign exchange sectors and among the equity markets of Egypt, Kenya, Nigeria, South Africa and Tunisia. The main findings suggest a higher dependence of own return in the stock markets and a one way return spillover from the currencies to the equity markets except for South Africa which has a weaker interrelation among the two markets. There is a relatively limited integration among the equity markets. Return and volatility spillover is mostly uni-directional except for a bi-directional relationship between the equity markets of Egypt and Tunisia. The study implication still proves a benefit for portfolio managers diversifying in these African equity markets, since they are independent of each other and may not be highly affected by the influx of negative news from elsewhere. However, there is the need to be wary of return and volatility spillover between the equity and currency markets, hence devising better hedging strategies to curb them.

Variance reduction properties of dynamic hedging models - empirical evidence from BRICS countries

This Master’s Thesis analyses the effectiveness of different hedging models on BRICS (Brazil, Russia, India, China, and South Africa) countries. Hedging performance is examined by comparing two different dynamic hedging models to conventional OLS regression based model. The dynamic hedging models being employed are Constant Conditional Correlation (CCC) GARCH(1,1) and Dynamic Conditional Correlation (DCC) GARCH(1,1) with Student’s t-distribution. In order to capture the period of both Great Moderation and the latest financial crisis, the sample period extends from 2003 to 2014. To determine whether dynamic models outperform the conventional one, the reduction of portfolio variance for in-sample data with contemporaneous hedge ratios is first determined and then the holding period of the portfolios is extended to one and two days. In addition, the accuracy of hedge ratio forecasts is examined on the basis of out-of-sample variance reduction. The results are mixed and suggest that dynamic hedging models may not provide enough benefits to justify harder estimation and daily portfolio adjustment. In this sense, the results are consistent with the existing literature.

Active Magnetic Bearing System Identification Methods and Rotor Model Updating

Active magnetic bearing is a type of bearing which uses magnetic field to levitate the rotor. These bearings require continuous control of the currents in electromagnets and data from position of the rotor and the measured current from electromagnets. Because of this different identification methods can be implemented with no additional hardware. In this thesis the focus was to implement and test identification methods for active magnetic bearing system and to update the rotor model. Magnetic center calibration is a method used to locate the magnetic center of the rotor. Rotor model identification is an identification method used to identify the rotor model. Rotor model update is a method used to update the rotor model based on identification data. These methods were implemented and tested with a real machine where rotor was levitated with active magnetic bearings and the functionality of the methods was ensured. Methods were developed with further extension in mind and also with the possibility to apply them for different machines with ease.

Relay protection in active distribution networks

Increasingly growing share of distributed generation in the whole electrical power system’s generating system is currently a worldwide tendency, driven by several factors, encircling mainly difficulties in refinement of megalopolises’ distribution networks and its maintenance; widening environmental concerns adding to both energy efficiency approaches and installation of renewable sources based generation, inherently distributed; increased power quality and reliability needs; progress in IT field, making implementable harmonization of needs and interests of different-energy-type generators and consumers. At this stage, the volume, formed by system-interconnected distributed generation facilities, have reached the level of causing broad impact toward system operation under emergency and post-emergency conditions in several EU countries, thus previously implementable approach of their preliminary tripping in case of a fault, preventing generating equipment damage and disoperation of relay protection and automation, is not applicable any more. Adding to the preceding, withstand capability and transient electromechanical stability of generating technologies, interconnecting in proximity of load nodes, enhanced significantly since the moment Low Voltage Ride-Through regulations, followed by techniques, were introduced in Grid Codes. Both aspects leads to relay protection and auto-reclosing operation in presence of distributed generation generally connected after grid planning and construction phases. This paper proposes solutions to the emerging need to ensure correct operation of the equipment in question with least possible grid refinements, distinctively for every type of distributed generation technology achieved its technical maturity to date and network’s protection. New generating technologies are equivalented from the perspective of representation in calculation of initial steady-state short-circuit current used to dimension current-sensing relay protection, and widely adopted short-circuit calculation practices, as IEC 60909 and VDE 0102. The phenomenon of unintentional islanding, influencing auto-reclosing, is addressed, and protection schemes used to eliminate an sustained island are listed and characterized by reliability and implementation related factors, whereas also forming a crucial aspect of realization of the proposed protection operation relieving measures.

OMXH 25-yhtiöiden valuuttariski ja siltä suojautuminen

Tämän kandidaatintutkielman tavoitteena on selvittää OMXH 25-yhtiöiden altistumista valuuttariskille ja kuinka nämä yhtiöt suojautuvat siltä. Tässä tutkimuksessa on lisäksi selvitetty näiden yhtiöiden tärkeimmät ulkomaanvaluutat ja yhtiöiden suojausstrategioita. Valuuttariskin suuruuden selvittämiseksi yhtiöiden vieraan valuuttaista liikevaihtoa verrattiin yhtiön kokonaisliikevaihtoon. Tutkimuksen aineistona on käytetty yhtiöiden vuosien 2013 ja 2014 tilinpäätöksiä. Aineistosta on lisäksi rajattu pois OMXH 25-yhtiöiden joukosta Nordea, Sampo, Elisa ja Telia Sonera. Nämä yhtiöt rajattiin pois, koska ne soveltuivat huonosti tämän tutkimuksen kohteiksi. Tutkimuksen teoriakehys on rakennettu keskeisten teorioiden ja käsitteiden avulla. Valuuttariski voidaan jakaa kolmeen osaan: transaktioriskiin, ekonomiseen riskiin ja translaatioriskiin. Valuuttariskin suojauksessa käytettävät instrumentit ovat termiinit, optiot, swap-sopimukset ja vieraan valuuttainen velka. Myös suojaamatta jättämisen mahdollisuutta on tutkittu. Tutkimuksessa kävi ilmi yhtiöiden merkittävä altistuminen valuuttariskille liikevaihdolla mitattuna. Yhtiöiden liikevaihdosta lähes 50% tapahtui jossain muussa valuutassa kuin euroissa. Yhtiöt käyttävät valuuttariskiltä suojautumiseen pääasiassa termiinejä, mutta myös muita instrumentteja käytetään jonkin verran. Yhtiöt keskittyvät eniten transaktioriskin suojaamiseen ekonomisen riskin ja tranlaatioriskin jäädessä pienemmälle huomiolle. Myös aikaisemmissa tutkimuksissa on saatu samankaltaisia tuloksia. Viime vuosien voimakkaat valuuttakurssimuutokset ovat vaikuttaneet yhtiöiden tuloksiin negatiivisesti ja erityisesti ruplan arvon voimakas heikentyminen suhteessa euroon aiheutti joillekkin yhtiöille merkittäviä valuuttakurssitappioita. Tärkein vieras valuutta tutkituille yhtiöille oli USA:n dollari. Korkeasta suojausasteesta huolimatta suurinosa tutkituista yhtiöistä kärsi valuuttakurssitappiota kumpanakin tarkasteltuna vuonna.

Derivative hedging strategies for bitumen price risk

The objective of the study is to extend the existing hedging literature of the commodity price risks by investigating what kind of hedging strategies can be used in companies using bitumen as raw material in their production. Five different alternative swap hedging strategies in bitumen markets are empirically tested. Strategies tested are full hedge strategy, simple, conservative, and aggressive term structure strategies, and implied volatility strategy. The effectiveness of the alternative strategies is measured by excess returns compared to no hedge strategy. In addition, the downside risk of each strategy is measured with target absolute semi-deviation. Results indicate that any of the tested strategies does not outperform the no hedge strategy in terms of excess returns in all maturities. The best-performing aggressive term structure strategy succeeds to create positive excess returns only in short maturities. However, risk seems to increase hand-in-hand with the excess returns so that the best-performing strategies get the highest risk metrics as well. This implicates that the company willing to gain from favorable price movements must be ready to bear a greater risk. Thus, no superior hedging strategy over the others is found.