This study examines the impact of reducing tick size and, in particular decimalization on stock splits. Based on previous studies, this study examines hypotheses in the following three areas: first, market reaction around stock split announcement and ex-dates, second, the effect of tick size on liquidity after stock split ex-dates, and third, the effect of tick size on return volatility after stock split ex-dates. The impact of tick size on market reaction around split announcement and ex-dates is measured by abnormal returns and buy and hold abnormal returns (BHARs). Also, this study investigates the long term impact of decimalization on market reaction for small, medium, and large firms for the three different tick size periods. The effect of tick size on liquidity after stock split ex-dates is measured by turnover, relative bid ask spread, and market maker count. The effect of tick size on return volatility around stock split announcement and ex-dates is measured by return standard deviation. Also, this study investigates the long term impact of decimalization on volatility after split ex-dates for small, medium, and large firms for three different tick size periods.

The purpose of this thesis is to analyze differences between IPOs with integer (e.g. $20,00) and non-integer (e.g. $20,32) offer prices on the post-decimalization US market. Research on IPOs suggests that there are viable differences between, and valuable information within, integer and non-integer prices. However, proposed effects on the information content of prices as a result of decimalization on US markets in 2001 motivates more up-to-date research on the subject. Our findings show that, while integer IPOs have higher initial return, uncertainty and offer price levels, there is no proof of different information content conveyed within integer and non-integer prices on the post-decimalization market. Consequently, suggesting that neither integer or non-integer prices provide valuable information to market participants, and in extension that decimalization may have influenced the IPO market. / Syftet med den här uppsatsen är att analysera skillnader mellan börsnoteringar med teckningskurser formulerade i heltal (t.ex. $20,00) och icke-heltal (t.ex. $20,32) efter decimaliseringen på den amerikanska marknaden. Tidigare studier har funnit stor skillnad mellan, och värdefull information inom, heltals- och icke-heltalskurser. Efter decimaliseringen på den amerikanska marknaden 2001 har studier dock funnit att prisers informationsinnehåll kan ha förändrats, vilket motiverar mer aktuell forskning inom ämnet. Våra resultat visar att även om börsnoteringar med heltals-kurser har högre initial avkastning, osäkerhet och teckningskursnivå, finns det inga tecken på att det är någon skillnad i informationsinnehåll mellan heltals- och icke-heltalskurser på den amerikanska marknaden efter decimaliseringen. Våra resultat antyder att det inte finns någon värdefull information för marknadsaktörer i huruvida en börsnoterings teckningskurs är formulerad i heltal eller icke-heltal, och i förlängningen att decimaliseringen kan ha påverkat marknaden för börsnoteringar.