There are other signs that confidence in the trade is slipping.
The Bofa survey found a net 6 percent of European fund managers see the region's equities as overvalued, the highest since the valuation bubble in 2000. Global fund managers' conviction on the trade has also been waning, with a net 21 percent expecting to be overweight Europe stocks on a 12-month view, down from a 40 percent reading in February, the Bofa survey found.
To be sure, Nomura noted that it is only disappointed with the pace of recovery.
"We are 'pushing out' our modest earnings optimism into the future, rather than bailing on this call altogether," Nomura said. "We still expect a positive return in absolute terms and from an asset allocation perspective still prefer European equities to European government bonds."
It maintains its index target for Europe ex-U.K., suggesting 7 percent upside from here through the end of the year.
Others are sticking with the trade, but with some misgivings.
Read More Fund managers see further gains for stocks
"There are occasions, unfortunately, when you've just got to run with the herd," Stephen Davies, CEO of Javelin Wealth Management, told CNBC.
"With the ECB showing absolutely no sign of changing its very accommodative approach, that definitely means you'll be benefiting from low interest rates, or effectively negative real interest rates for the foreseeable future," Davies said. "That's positive for banks. It's positive for the broader market in general."
—By CNBC.Com's Leslie Shaffer; Follow her on Twitter