0394650 20240103202759.820140314235959.9 6 s. C cav_un_epca*0395722978-80-87035-76-4JihlavaCollege of Polytechnics Jihlava2013VojáčkováHana portfolio competition game theory behavioural finance cav_un_auth*0264564 Kuběna Aleš Antonín Ekonometrie Department of Econometrics E E UTIA-B Department of Econometrics Ústav teorie informace a automatizace AV ČR, v. v. i. cav_un_auth*0101206 Šmíd Martin Ekonometrie Department of Econometrics E E UTIA-B Department of Econometrics Ústav teorie informace a automatizace AV ČR, v. v. i. http://library.utia.cas.cz/separaty/2013/E/kubena-portfolio competitions and rationality.pdf GA402/09/0965 GA ČR cav_un_auth*0253176 We study investment competitions in which the players with highest achieved returns are rewarded by fixed prizes. We show that, under realistic assumptions, a game the participants play lacks a pure equilibrium and that the ``max-min'' solution of the game lies in one of the extremal points of the feasible set, namely in the one having maximal probability that the portfolio return falls into its normal cone. We analyse empirically a portfolio competition held recently by the Czech portal ``lidovky.cz''; we find that the majority of people do not behave according to the game-theoretic conclusions. Consequently, searching for factors influencing a choice of particular stocks, we find that that the only significant determinant of the choice is a size of the stock's issuer. cav_un_auth*0292039 MME 2013. International Conference on Mathematical Methods in Economics 2013 /31./ Jihlava 11.09.2013-13.09.2013 CZ 2014 BB 2 PR RVO:67985556 http://hdl.handle.net/11104/0223253 1 S 2013 cav_un_epca*0395722 Proceedings of the 31st International Conference Mathematical Methods in Economics 2013 978-80-87035-76-4 Jihlava College of Polytechnics Jihlava 2013 Vojáčková Hana 340