RFE means Request For Further Evidence. If USCIS has questions about certain aspects of the I-526 petition, they send in an RFE. Typically, but not necessarily, this occurs within the context of the source of funds. If the investor has not provided sufficient documentation on how he had obtained the funds to fund the investment, this might occur. Recently, the courts ruled that borrowed funds do not need to be collateralized. As of this writing, we are unclear how USCIS plans to change its policy because of this ruling. Up until now, the policy of USCIS has been as follows

• If the investor uses borrowed funds, then they need to collateralize the loan. Furthermore, they must show the source of the funds used to purchase the collateral used to borrow the funds from the lender.
• If the investor obtains the funds through a gift, the gifter has to show the source of the funds.