Because they do not trade on a stock exchange, non-traded REITs involve special risks:

Lack of Liquidity

Non-traded REITs are illiquid investments. They generally cannot be sold readily on the open market. If you need to sell an asset to raise money quickly, you may not be able to do so with shares of a non-traded REIT.

Share Value Transparency

While the market price of a publicly traded REIT is readily accessible, it can be difficult to determine the value of a share of a non-traded REIT. Non-traded REITs typically do not provide an estimate of their value per share until 18 months after their offering closes. This may be years after you have made your investment. As a result, for a significant time period you may be unable to assess the value of your non-traded REIT investment and its volatility.

Distributions May Be Paid by Offering Proceeds and Borrowings

Investors may be attracted to non-traded REITs by their relatively high dividend yields compared to those of publicly traded REITs. Unlike publicly-traded REITs, however, non-traded REITs frequently pay distributions in excess of their funds from operations. To do so, they may use offering proceeds and borrowings. This practice, which is typically not used by publicly-traded REITs, reduces the value of the shares and the cash available to the company to purchase additional assets.

Conflicts of Interest

Non-traded REITs typically have an external manager instead of their own employees. This can lead to potential conflicts of interest with shareholders. For example, the REIT may pay the external manager significant fees based on the number of property acquisitions and assets under management. These fee incentives may not necessarily align with the interests of shareholders.

Source:
US Securities and Exchange Commission