Strategists in the poll were nearly split on the direction the euro would take through the month, with 28 of 61 expecting it to weaken and 33, including Banco BPI, calling for a slight gain instead.
The euro strengthened by 0.8 percent to end October at $1.30, right on the bank's target.
The Lisbon-based FX strategy team at Banco BPI are the first to clinch the top spot in the monthly league twice in a row since the start of the global financial crisis in 2008.
In the latest poll, published on Friday, Banco BPI expects the euro to hold steady at $1.30 in a month before gaining to $1.32 in six months and $1.34 in a year.
This is in contrast with the medians of the poll that show the euro gradually weakening over the course of a year to $1.25 instead.