The Treasury Department will soon outline rules stemming from the $1.5 trillion tax overhaul last year that are aimed at giving investors confidence to pour billions of dollars into distressed areas. Investment banks, venture capitalists, and real estate developers have been eagerly awaiting guidance for so-called opportunity zones. These zones are identified to attract capital to areas where investment has lagged by allowing investors to avoid some taxes when they fund projects there. But critics have warned that this could just hasten gentrification and serve as a tax shelter for wealthy investors.