Secondary investments refer to investments made in existing private equity assets. These transactions can involve the sale of private equity fund interests or portfolios of direct investments in privately held companies through the purchase of these investments from existing institutional investors. By its nature, the private equity asset class is illiquid, intended to be a long-term investment for buy and hold investors. Secondary investments provide institutional investors with the ability to improve vintage diversification[clarify], particularly for investors that are new to the asset class. Secondaries also typically experience a different cash flow profile, diminishing the j-curve effect of investing in new private equity funds. Often investments in secondaries are made through third-party fund vehicle, structured similar to a fund of funds although many large institutional investors have purchased private equity fund interests through secondary transactions. Sellers of private equity fund investments sell not only the investments in the fund but also their remaining unfunded commitments to the funds.