In October, the Supreme Court opens its new term with a case most Americans have never heard of, and it will decide something that should worry every worker with a 401(k): whether the fiduciaries who pick your retirement investments can hide behind opacity itself. The October argument calendar, released this month, confirms Anderson v. Intel Corp. Investment Policy Committee will be argued that day. The timing fits. Washington spent this year building a wide-open door for private equity, private credit, and other hard-to-value assets to enter your retirement account, and it is now asking the justices to make sure nobody can hold a fiduciary accountable once those assets walk through it. I have spent over 30 years structuring and valuing private credit and private equity positions for institutional and ultra-high-net-worth clients. I have watched two equally credentialed managers mark the identical position 10 or 15 points apart and both call it prudent. That is not a hypothetical for me. It is Tuesday. So, when Washington tells 90 million 401(k) participants that this asset class is ready for their retirement savings, my first question is not whether the returns are attractive. It is who verifies the price. The opacity's mechanics aren't in dispute. A scholar's brief filed with the Supreme Court in the Anderson case lays them out, with citations. At the start of this decade, mutual funds held 58% of target-date assets, the default option in most 401(k)s, against 42% for collective investment trusts. That has flipped: as of June 30, 2026, CITs held 55% and mutual funds 45%, according to Sway Research's mid-year 2026 report. Only six new mutual fund target-date series have launched since 2020, the most recent in 2024, against 75 new CIT series. Combined mutual fund and CIT target-date assets have grown 88% since 2022, reaching $5.3 trillion this June. CITs remain exempt from the Investment Company Act of 1940 and the Securities Act of 1933, and industry-wide they hold roughly $7 trillion, nearly 30% of all defined-contribution assets. A federal audit found that even the fiduciaries selecting these vehicles often cannot make sense of the paperwork: the Government Accountability Office reported in 2024 that CIT disclosure formats are inconsistent and that plan sponsors “may not understand” them. Morgan Stanley's own marketing materials concede that CITs “are not subject to the extensive registration, operational, disclosure, and reporting requirements of federal and state securities laws.” That is the sales pitch, not the fine print. Layer alternative assets onto that structure and the opacity compounds. State Street Investment Management and Apollo Global Management are already building target-date series with direct allocations to private assets, one of several partnerships driving that migration, per Sway's report. Private credit and private equity are not priced by the market. They are priced by the people who sold them to you, using models and appraisals that update on their schedule, not yours. When Apollo and KKR marked the same stressed private loan last November, one called it worth 77 cents on the dollar and the other called it 91, a 14-point gap on the identical asset. Liquidity tells the same story. Carlyle's private-credit fund took in redemption requests equal to 15.7% of assets this spring; Blue Owl saw requests running from 16% to more than 40% of shares. Both capped withdrawals at 5%, gates that are standard practice in private funds and entirely foreign to the daily liquidity a 401(k) participant expects when she wants to rebalance. President Donald Trump's August 2025 executive order, Democratizing Access to Alternative Assets for 401(k) Investors, directed the Labor Department to clear the path, and it did: a March 2026 proposed rule builds fiduciaries a process-based safe harbor for adding these assets to plan menus. Fair enough. Public pensions and endowments have used private markets profitably for decades, and a documented process is a legitimate ambition. But the same Labor Department also filed a brief with the Supreme Court urging it to require plaintiffs to plead a “meaningful benchmark” before they can even reach discovery, precisely the information a bespoke, unregistered CIT won't surrender without a subpoena. And in April, the agency told its own investigators to stop second-guessing fiduciaries' process decisions and focus only on the most egregious, bad-faith cases, a retreat from the routine scrutiny that used to catch problems before they reached a courtroom. To be sure, the plaintiffs' bar has filed its share of opportunistic underperformance suits, and a fiduciary shouldn't face years of litigation because a risk-mitigating fund trailed the S&P 500 in a bull market. The Ninth Circuit's demand for a comparator has real logic behind it. But that logic collapses when the asset itself is designed to prevent comparison. A benchmarking rule that requires disclosure nobody must give doesn't filter frivolous suits. It filters out the only suits that could ever be proven. Here is the arithmetic Washington keeps skipping. A fiduciary duty that cannot be verified is not a fiduciary duty. It is a marketing claim with a legal disclaimer attached. If the government wants private equity and private credit inside 90 million retirement accounts, it owes those accounts the same baseline it demands of every mutual fund on the shelf: standardized, public, apples-to-apples disclosure of fees, valuation methodology, and liquidity terms, whatever wrapper the asset arrives in. Congress and the DOL can build that floor before the CIT migration finishes, or they can watch the Supreme Court build a ceiling over discovery instead. One of those outcomes protects retirement savers. The other protects everyone else.