Subject: File No. SR-CHX-2016-20
From: Susan Williams
Affiliation: Risk Analyst, Blue Stone Capital

September 17, 2017

Dear SEC Commissioners:

I want to bring to light the purported CFIUS approved transaction involving the Chicago Stock Exchange and a Chinese company in which Im still trying to understand.

The NA Casin Group is currently in the process of trying to buy the Chicago Stock Exchange with the transaction passing the CFIUS review back in December. However, when looking into the investors involved, 75% of them are tied to empty shell companies registered to low income housing surrounding Flushings Chinatown in Queens, New York. How can a group like this afford to buy a stock exchange, unless something is obviously being hidden?

Casin Development was halted by the Shenzhen Stock Exchange in May 2017 for hundreds of millions of dollars of undisclosed collateralized stock loans by ShengJu Lu, Casin's owner and Chairman, from the state run Peoples HengFeng Bank. The stock plummeted from RMB 69 to zero. (See Google Finance, Casin stock code: 000838 Shenzhen Stock Exchange) Public shareholders lost more than $1 Billion. Casin is now under investigation and undergoing a "restructuring."

Why is this not a huge red flag? Why was this approved by CFIUS in December, and why did the SEC staff not take this under consideration before approving the transaction in August?

Regards,

Susan Williams