February 3, 2020

Vanessa Countryman
Secretary
Securities and Exchange Commission
100 F Street NE., Washington, DC 20549

Re: SIFMA Comment Letter on IEX Proposed Rule Change to Add a New Discretionary Limit Order Type; File No. SR-IEX-2019-15

Dear Ms. Countryman:

The Securities Industry and Financial Markets Association (“SIFMA”)1 respectfully submits this letter to comment on the proposed rule change by the Investors Exchange LLC (“IEX”) to offer a new discretionary limit order type (“D-Limit Order”).2 We strongly support innovation in the U.S. equity markets. IEX has certainly provided some unique offerings to the marketplace over the years that have benefited certain market participants. For the reasons discussed more fully below, however, with respect to the proposed D-Limit Order, SIFMA is concerned about quote accessibility as a result of a displayed limited order being repriced based on IEX’s crumbling quote indicator (“CQI”), especially if there is broader adoption of the order type by other exchanges.3 We believe that these concerns could be lessened if IEX were to offer this order type as “un-protected”.

By way of background, SIFMA has previously expressed concern with asymmetrical speed bumps and their impact on U.S. equity market structure,4 as a proposed alternative for liquidity provision. SIFMA commends IEX for its proposal to provide another alternative for liquidity provision. With each such alternative, however, SIFMA believes that the SEC should carefully consider and address broader market implications of any new proposed exchange functionality and order types that are offered by one exchange given that they could then be offered by other exchanges. In considering whether to approve this order type, the SEC should assume that other exchanges would adopt similar order types when considering the implications on the national market system.