Arvostrategioiden menestys Suomen osakemarkkinoilla

Tämän tutkimuksen tavoitteena on selvittää saavutetaanko passiivisilla arvostrategioilla riskikorjattuna ylisuuria tuottoja Suomen osakemarkkinoilla. Tuottaako matalien tunnuslukujen perusteella valittujen osakkeiden portfolio enemmän kuin korkeiden tunnuslukujen portfolio? Ovatko alfat tilastollisesti merkitseviä? Tutkimuksen tavoitteena on myös selvittää, ovatko korkeimman ja matalimman arvostustason portfolioiden menestyserot tilastollisesti merkitseviä. Tunnuslukuina on tarkasteltu P/E-, EV/EBIT- ja EV/EBITDA-tunnuslukuja sekä P/B- ja P/S–lukuja. Lisäksi on tutkittu yhdistelmätunnuslukuina P/E- ja P/B–lukujen tulon muodostamaa tunnuslukua, sekä suhteellisiin EV/EBITDA-, P/B- ja P/S-lukuihin perustuvaa arvostusmittaria. Tutkimusaineisto koostuu Suomen osakemarkkinoilla julkisesti noteeratuista yrityksistä toukokuusta 1991 toukokuuhun 2006. Osakkeet järjestettiin tunnuslukujen arvostustason perusteella kvintiiliportfolioihin. Myöhemmin portfoliot muodostettiin uudelleen kolmen ja viiden vuoden välein. Lopuksi tarkasteltiin kvintiiliportfolioiden kuukausittaisia tuottoja tunnuslukukohtaisesti koko tutkimusjakson ajalta. Tulosten perusteella on selkeästi havaittavissa, että matalan tunnusluvun kvintiiliportfoliot menestyivät paremmin kuin korkean tunnusluvun kvintiiliportfoliot. Kolmen vuoden jaksoissa P/E-, EV/EBITDA-, P/B-, P/S- ja kolmen tunnusluvun yhdistelmällä muodostetuilla kvintiiliportfolioilla arvopreemio oli selkeästi havaittavissa. Viiden vuoden jaksoissa vastaava ilmiö toistui EV/EBITDA-tunnusluvulla muodostetuilla kvintiiliportfolioilla. Eniten tuotti absoluuttisesti sekä riskikorjattuna tutkimuksessa esiteltävä kolmen vuoden jaksoissa kolmen tunnusluvun yhdistelmällä muodostettu matalimman arvostustason kvintiiliportfolio, joka tuotti riskikorjattuna tilastollisesti erittäin merkitsevästi positiivista alfaa matalalla riskitasolla.

Free Flap Monitoring. Using Tissue Oxygen Measurement and Positron Emission Tomography

Aims:This study was carried out to evaluate the feasibility of two different methods to determine free flap perfusion in cancer patients undergoing major reconstructive surgery. The hypotheses was that low perfusion in the flap is associated with flap complications. Patients and methods: Between August 2002 and June 2008 at the Department of Otorhinolaryngology – Head and Neck Surgery, Department of Surgery, and at the PET Centre, Turku, 30 consecutive patients with 32 free flaps were included in this study. The perfusion of the free microvascular flaps was assessed with positron emission tomography (PET) and radioactive water ([p>15p>O] H₂O) in 40 radiowater injections in 33 PET studies. Furthermore, 24 free flaps were monitored with a continuous tissue oxygen measurement using flexible polarographic catheters for an average of three postoperative days. Results: Of the 17 patients operated on for head and neck (HN) cancer and reconstructed with 18 free flaps, three re-operations were carried out due to poor tissue oxygenation as indicated by p</i>_tiO₂ monitoring results and three other patients were reoperated on for postoperative hematomas in the operated area. Blood perfusion assessed with PET (BF_PET) was above 2.0 mL / min / 100 g in all flaps and a low flap-to-muscle BFPET ratio appeared to correlate with poor survival of the flap. Survival in this group of HN cancer patients was 9.0 months (median, range 2.4-34.2) after a median follow-up of 11.9 months (range 1.0-61.0 months). Seven HN patients of this group are alive without any sign of recurrence and one patient has died of other causes. All of the 13 breast reconstruction patients included in the study are alive and free of disease at a median follow-up time of 27.4 months (range 13.9-35.7 months). Re-explorations were carried out in three patients due data provided by p</i>_tiO₂ monitoring and one re-exploration was avoided on the basis of adequate blood perfusion assessed with PET. Two patients had donorsite morbidity and 3 patients had partial flap necrosis or fat necrosis. There were no total flap losses. Conclusions: P</i>_tiO₂ monitoring is a feasible method of free flap monitoring when flap temperature is monitored and maintained close to the core temperature. When other monitoring methods give controversial results or are unavailable, [₁₅O] H₂O PET technique is feasible in the evaluation of the perfusion of the newly reconstructed free flaps.

De principiis primis

Osa nimekkeestä ladottu kreikkalaisin kirjaimin.

Added Value of Combining Value and Momentum Indicators in the Swiss Stock Market

The purpose of the thesis is to examine the added value of combining value and momentum indicators in the Swiss stock exchange. Value indicators employed are P/E, EV/EBITDA, P/CF, P/B ja P/S. Momentum indicators examined are 52-week high, acceleration rate, 12-month past return and 6-month past return. The thesis examines whether the composite value measures based on the above mentioned ratios can add value and whether the inclusion of momentum can further improve the risk return profile of the value portfolios. The data is gathered from the Swiss equity market during the sample period from May 2001 to May 2011. Previous studies have shown that composite value measures can somewhat add value to the value portfolio strategy. Similarly, recent academic literature have found evidence that momentum works well as a timing indicator for time to entry to value stocks. This study indicates that the added value of composite value measures exists. It also shows that momentum combined to acceleration rate can significantly improve the risk adjusted performance of value-only portfolios.

De principiis primis

Variantti A.

De principiis primis

Variantti B.