"European, largely German institutional investors have grown fond of assets ranging from New York offices to Pan-American logistics," Sethuraman added in the report. "Right now, we're of course at a significant moment in terms of price rediscovery; reassessment of existing positions is foreseeable."

The drop in U.S. interest rates has also helped U.S.-dollar denominated investors who recently bought in Europe, provided they used cross-currency swaps to hedge their investments. Investments made a year again likely have an equity position that's increased by 8% over that interval, according to the report. And overall returns could have increased by as much as 23% if leveraged to roughly 65%.

Currency fluctuations are also making a difference. The JLL report points to the example of Norway, where energy market volatility has led to the depreciation of the krone since the start of the calendar year. In March, it reached its lowest point against the U.S. dollar since 1971.

Norway has emerged as a major source of overseas capital in recent years, and as a result of the recent plunge in the krone, the Norwegian investors who bought U.S. dollar-denominated assets in the past five years have seen the value of these investments jump.

"Norwegian investors – a significant force in real estate markets across the world – may now find that their overseas equity is worth a lot more," JLL global derivates director Adam Liden, said in the report.

That could prompt them to cash out, Liden added, noting that a Norwegian investor who invested in euros in 2015 is likely to have seen equity increase by 35% over five years due to the drop in the krone.

Meanwhile, South Korean investors, who've seen their currency drop in relation to the euro, are changing the focus of their activity on the continent. 

"There's been a notable shift made by South Korean investors to central and eastern European cities over the past 12 to 18 months," Sethuraman added, naming Poland and the Czech Republic in particular.