Wouldn't an hour of trading a day be enough if the EMH were true?

If the efficient market hypothesis were true, wouldn't prices be able to adjust to all available information in a very short amount of time? As such, is there any benefit of the market being open any more than an hour a day?

Submitted December 29, 2016 at 11:27AM by acvdk http://ift.tt/2ic0Ryh