1. INTRODUCTION Many works had been published, in Brazil and the exterior, with the objective to verify if the market of options and other derivativosinfluencia the price of the underlying assets negotiated the sight, in the day and tornodo expiration of these contracts. This influence is related the possible manipulations domercado the sight. Trader with a great position in contracts of it opoou of futures can be attemped to manipulate the price of the underlying asset, sejacomprando or vendendo this asset, before the expiration. The loss in the market sights is compensated by the profit in the market of derivatives. In this study, it is analyzed, the intradirio level, orelacionamento enters the activity of the market of options and the variations of preodo active underlying in the market the sight, in the Stock exchange of So Paulo. Main Ofoco is the activity of the market of purchase options and if this affects avolatilidade of the market the sight of the action-object. Since the pioneering work of Klemkosky (1978) on the efeitodia of expiration in the market American north, diverse authors if interessarampelo subject.
In Brazil it was not different, Brito and Sosin (1984) and Sanvicente eKerr (1989) had been the first national authors to apply the method deKlemkosky, of study of events, the data of the Stock exchange of the River of Janeiroe of So Paulo, respectively. To the measure that information more detailed on quotations deaes, of options and other derivatives had been being spread dedados way bank, the studies if sophisticating and focusing had been given intradirios. Oprimeiro study with this type of data and focus in the effect day of expiration (of future contracts) was of Stoll and Whaley (1987), in U.S.A. In Brazil, oprimeiro and only work on the subject until the moment are of eMonteiro Sanvicente (2005) that it evidenced, saw a model of simultaneous equations, aexistncia of manipulation of prices during the day of contract expiration deopes on the actions of the Telemar company.