In science and engineering it's the difference between what calculus calls the first and second derivatives: how fast something is changing and then the shift in that rate of change. For commercial real estate properties overall, April was good news in the former and, depending on the view, less happy tidings for the latter, according to Real Capital Analytics. 

The RCA CPPI National All-Property Index from MSCI was up 17.9% year over year in April. Industrial (26.0% growth) and multifamily (23.0%) were the leaders. Retail saw an 18.4% boost. Office, up by 11.8%, varied by the type of location, with central business district properties rising 12.3%, significantly higher than the 10.3% lift for suburban. Property prices in general were up 19.8% in major non-metro areas compared to 11.8% in major metros.

But that's the historical look. That second derivative—the rate at which change gets larger or smaller—is the language of the present gazing ahead into the future as industry professionals try to prepare for it. On that front, the news could be disappointing or actually good, depending on where you stand.