Commitments and Contingencies As of September 30, 2018 , the Company had commitments to acquire 196 single-family properties for an aggregate purchase price of $48.3 million , as well as $67.3 million in purchase commitments that relate to both third party developer agreements and land for our internal construction program. As of December 31, 2017 , the Company had commitments to acquire 520 single-family properties for an aggregate purchase price of $128.1 million , as well as $24.0 million in purchase commitments that relate to both third party developer agreements and land for our internal construction program. As of September 30, 2018 , and December 31, 2017 , the Company had sales in escrow for approximately 155 and 69 of our single-family properties, respectively, for aggregate selling prices of $23.9 million and $7.0 million , respectively. We are involved in various legal and administrative proceedings that are incidental to our business. We do not believe these matters will have a material adverse effect on our financial position or results of operations upon resolution. Radian Group Inc. (Radian), the indirect parent company of Green River Capital LLC (GRC), which has been a service provider that provided certain broker price opinions (BPO) to us, disclosed in its Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2017, that GRC had received a letter in March 2017 from the staff of the SEC stating that it is conducting an investigation captioned In the Matter of Certain Single Family Rental Securitizations and requesting information from market participants. Radian disclosed that the letter asked GRC to provide information regarding BPOs that GRC provided on properties included in single family rental securitization transactions (Securitizations). On September 13, 2017, we received a letter from the staff of the SEC stating that it is conducting an investigation captioned In the Matter of Certain Single Family Rental Securitizations. The letter enclosed a subpoena that requests the production of certain documents and communications related to our Securitizations, including, without limitation, those related to BPOs provided by GRC on properties included in Securitizations. The letter does not allege any violation of law and we are cooperating with the SEC. We understand that other transaction parties in Securitizations have received requests in this matter. We do not believe this matter will have a material adverse impact on our financial position or results of operations upon resolution. On January 16, 2018, we received a letter from the staff of the SEC stating that it is conducting an investigation captioned Trading in Silver Bay Realty Trust Corp. The letter enclosed a subpoena that requests us to produce certain documents and communications, including those related to our communications and agreements with Silver Bay Realty Trust Corp. (Silver Bay), communications with Silver Bays financial advisor, and our purchases, sales and holdings of Silver Bay stock. We purchased Silver Bay stock in 2016 and 2017 and then sold all of our holdings in 2017 for a profit of approximately $3.0 million . We intend to continue to cooperate fully with the SEC in connection with this matter. We do not believe this matter will have a material adverse impact on our financial position or results of operations upon resolution.