The latest developments suggest the gap in the polls has widened not just because voters are abandoning the leave campaign, but because undecided voters are making up their minds against Brexit. As the lead for remain widens, the key uncertainty on the day will be turnout -- recently undecided voters may feel less compelled to show up at the polls.

Eoin Treacy's view

Regardless of how one feels about what is a deeply divisive topic, there is little doubt that markets abhor uncertainty. With a vote to leave the EU representing a threat both to the status quo within and outside the region, the declining prospect of such an eventuality can only be viewed as positive from a short-term market perspective. 

The Pound experienced a deep decline from a 2014 peak near $1.70 to a low in March below $1.40 and a reversionary rally has already taken place which took the rate back to test the region of the trend mean. While a pause in the region of the early May peak is possible a sustained move below $1.43 would be required to question potential for additional higher to lateral ranging. 

The FTSE-100 has been ranging mostly below 7000 since 2000 and failed to sustain a move to new highs a year ago. It dropped by almost 30% following that failed upside break but has since rebounded to test the region of the trend mean and moved above it today. A sustained move below 6000 would now be required to question potential for additional upside.