Subject: Proposed Rule Change, File Number SR-BatsBZX-2017-34
From: Barry Zwarenstein
Affiliation: Five9, Inc.

August 11, 2017

Via Electronic Delivery
Mr. Brent J. Fields
Securities and Exchange Commission
100 F Street, N.E.
Washington, D.C.  20549

Dear Secretary Fields

I am writing to oppose the BATS proposal to create an alternative to the closing auctions run by NYSE and NASDAQ.

Such a proposal, if implemented, might bring some gains for brokers trading in Five9 (NASDAQ:FIVN), which may or may not flow back to shareholders, but would make the closing price less reliable.  This is because we do not have much liquidity in our stock to begin with and dissipating what little liquidity there is can only result in less accurate final end-of-day prices.

The importance of having an accurate and reliable closing price in a publicly trading company is self-evident.

Thank you,

Barry Zwarenstein

Barry Zwarenstein 
Chief Financial Officer

Five9, Inc. 
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