Looking at the overall prices of various securities as well as the trading volume, it seems the investment community is calling Tsipras's bluff. The way the market is reacting is actually strengthening the hands of EU. We needs to see what takes place after Greece misses the IMF payment on Tuesday. But if that does not lead to a market meltdown and Tsipras is running out of cards to play for the Sunday vote. The Greek voter will see the financial chaos in Greece itself as well as relative financial calm in the rest of EU. They will know which way they have to vote to get out of this.
Greeks who don't have anything to lose may well not care.