Public equity markets have been volatile recently, with a lot of downward movement. But even as stock markets have declined — including public real estate equities — private real estate values have appeared to hold steady.

Since early 2015, valuations for public and private real estate have diverged, especially in the U.S. markets, where, according to Peter Zabierek, CEO of Presima, “the divergence is the most striking and has been for a while.” And any time such a disconnect becomes apparent, investors are sure to ask: What does it mean?

And, much as the hoary joke that if you ask two economists about the market, you’ll get three opinions, plenty of disagreement surrounds the current public-private disconnect.

“It’s a very interesting signal that there are different opinions and strongly suggests it’s time to be cautious for the long-term investor,” says Andrew Allen, head of global property research and strategy at Aberdeen Asset Management.