Wall Street watchdogs are poised to take a major step toward overhauling Volcker Rule limits on banks’ ability to trade with their own funds, according to four people familiar with the effort, moving to ease post-crisis safeguards reviled by the industry. Regulators responsible for the Dodd-Frank Act rule could complete work as soon as next week on revisions that include loosening restrictions on banks investing their own money in private equity and hedge funds, according to the people, who requested anonymity because the process isn’t public.