It's been a busy month for Vanguard. Not only has it launched the UK's cheapest self-investment personal pension (Sipp) but it has announced a partnership with investment firm HarbourVest to start offering private equity investments. I confess to being puzzled by Vanguard’s news that it has partnered with a private equity investment firm, HarbourVest.Of all possible Vanguard additions, private equity seemed to be about the least likely. Vanguard serves mostly retail clients, with publicly traded securities, in liquid funds that carry very low expense ratios. In contrast, private equity investments are largely institutional, aren’t traded, and are owned by illiquid funds that are notably expensive. The fit, to put the matter gently, is not obvious.The timing is also perplexing. Vanguard is not known for entering “hot” markets. The company did not launch tactical-allocation funds following the 1987 stock crash, nor a technology fund during the New Era, nor alternatives funds 10 years back. In fact, Vanguard has frequently flouted the investment trends by temporarily closing the doors to its best-selling funds. Overall, its actions have been counter-cyclical. Private Equity Reaches RecordsNot this one. Research by PitchBook (a Morningstar subsidiary) in 2019 showed private equity investing is reaping record sales. Last year, the marketplace attracted $301 billion in new assets. That was its highest amount ever, exceeding the previous record of $267 billion, which was set in 2007. If that timing concerns you, it should. Historically, private equity has attracted the most capital at the worst times to invest, and the least capital at the best times.In its 2019 report on private equity, Bain & Company didn’t mince words. “For general partners [of private equity funds], putting record amounts of capital to work means getting comfortable with a certain level of discomfort when investing. They are paying prices they swore they would never pay and looking to capture value that may prove elusive.”Meanwhile, flows into global hedge funds have been roughly flat, down significantly from the previous decade. The reason for the discrepancy in sales between the two varieties of investment is depressingly simple. Private equity funds are more aggressive than hedge funds, and thus have been that much better suited to ride the 11-year stock bull market. They are in favor because they have performed relatively well, and they have performed relatively well because their style has been in favor.Has Vanguard conceded to fashion by offering what sells today, rather than what will benefit shareholders tomorrow? One certainly could interpret the move that way, particularly as Vanguard touts its forthcoming funds as being an “incredible opportunity” for “individual investors.” Those words had me holding my wallet.That said, Vanguard has spent 45 years doing the right thing for its shareholders. It may have done this time as well. After my initial critique, I took the opposite approach of attempting to think whether this private equity effort could be successful, and if so how. I decided in the affirmative, with two stipulations: 1\. Begin only with institutionsVanguard’s main occupation is managing funds for individuals but quietly, it has built a business serving small to mid-size pension funds. Such funds are increasingly emulating their larger peers by holding fewer conventional stocks and bonds, and more alternative investments – especially private equity.We can question whether this approach is ill-timed (as I just did), but I do not think that Vanguard should be chastised for selling private equity funds into this marketplace to meet its customers’ demands. After all, these clients are institutions. They are fully accountable for their asset-allocation choices. (Vanguard also serves as an outsourced chief investment officer for some institutions, which is a different arrangement, but I think that a similar logic applies).In contrast, bringing an asset class to individual investors is implicitly a recommendation. Fund companies, quite properly, are criticised for creating gimmick investments for mistiming their launches by selling high, thereby encouraging their shareholders to chase trends. It would be imprudent for Vanguard to rush private equity funds to individual buyers.Happily, that is not what the company is doing. Vanguard has stated that it will initially sell its private equity funds to institutions only. 2\. Revolutionise the pricingThroughout this missive, I have described Vanguard’s future offerings as “private equity funds,” but that was shorthand. Actually, they will be private equity funds of funds, because that is what HarbourVest does. It assembles portfolios of private equity funds, which are diversified not only in number, but also by type, as they include venture-capital, leveraged-buyout, and debt funds.This implies two levels of fees. The partnership of Vanguard/HarbourVest will levy an explicit fee for the duty of assembling the underlying funds. Meanwhile, the underlying funds will charge their own management fees, which are implicit from the viewpoint of the Vanguard fund-of-funds shareholders.The Vanguard/HarbourVest duo has full control over its explicit fee, which presumably will be low by private equity fund-of-funds standards (Vanguard hasn't yet discussed the topic). The real question, though, is whether the partnership can negotiate lower rates for its underlying funds, which are pricey indeed - typically carrying a 2% annual expense ratio, plus a performance fee that gives management a cut of the profits. No matter what Vanguard charges, its fund-of-funds won’t be cheap unless it can lower its vendor’s pricing.Whether this can be accomplished, we shall see. It’s worth noting, though, that large fund-of-funds managers such as HarbourVest are already using a process called “co-investing” to reduce their underlying costs, and that Vanguard historically has demanded--and received--substantial volume discounts. So, perhaps this admittedly ambitious goal can be accomplished.