Let us tarry again over one of the consequences of RET and EMH: the 19 If in were in their predictions be balanced with oth as many betting on a change away from the"true' value one way should shows that they ers betting the other way. bubbles could not grow, even though experience collapse. Hav- can and do grow, and moreover can be observed as bubbles even before they to arbitrage ing said that, there has been much research trying to square this circle limits to bet models which assume that though there may be(correct) naysayers otherwise willing aver against speculators in the act of creating a bubble, the naysayers' risk to sion and knowledge of the presence of less informed investors reduces their willingness for participate. So this type of amendment qualifies RET by, in effect, highlighting conditions this ts suspension or, if used merely to explain short-term aberrations, buttress it. Either way, supports the argument that EMH is wrong. And RET does not offer a convincing explanation of herd behaviour and of the empirical reality that large bubbles can form over long periods also behavioural