Effect of 2007-2008 credit crisis
The U.S. real estate market reached its peak in 2007, just before the 2007-2008 credit crisis when the property market collapsed. The value of commercial property returns dropped between 2007 and 2009. Since 2010, the market has steadily recovered, and the volume of transactions climbed until 2015, and has levelled out since then.
Types of commercial real estate
The change in overall transaction volume is most likely impacted by the type of commercial properties which are more attractive to investors in a particular period. For instance, the interest in multifamily housing investment opportunities went down in the same period that interest in hotel investment opportunities went up.