U.S. rules that determine who can invest in hedge funds and private equity are poised to get their most sweeping overhaul in years, though it’s unclear how much the changes will expand the pool of potential clients. In the coming weeks, the Securities and Exchange Commission will likely unveil a plan for updating the accredited investor standard, a bedrock that lays out the criteria for investing in riskier -- and potentially more lucrative -- private funds, said two people familiar with the matter.