The 875-room Grand Wailea Resort in Wailea, Hawaii, was the grand prize in the Government of Singapore Investment Corp.'s $1.64 billion portfolio sale earlier this year to the Blackstone Group. Government-owned investment funds, which were responsible for more than $10 billion in U.S. commercial property buys in 2017, have become net sellers of properties so far in 2018, according to CoStar transaction data. Moreover, these funds, commonly referred...