The move is a critical step in President Donald Trump’s push to open 401ks — the term for US retirement savings accounts — to private investment firms who see the system as a crucial market to draw in assets, particularly as large pensions and endowments pull back.

Employers would have to decide to offer the plans — and experts anticipate many might be reluctant, as they could be held liable for losses.

New rule opens 401(k) plans to private equity, prompting debate over benefits versus costs and transparency risks.