SecProbe.io

November 10, 2010
 Mr. Mark S. Casady Chief Executive Officer and Chairman LPL Investment Holdings Inc. One Beacon Street
Boston, MA 02108

Re: LPL Investment Holdings Inc.
Amendment No. 4 to Registrati on Statement on Form S-1
Filed November 3, 2010
  File No. 333-167325

Dear Mr. Casady:

We have reviewed your filing and have the following comments.  In some of our
comments, we may ask you to provide us with  information so we may better understand your
disclosure.
 Please respond to this letter by amending your registration statement and providing the
requested information.  If you do not believe  our comments apply to your facts and
circumstances or do not believe an amendment is appropriate, please tell us why in your
response.
 After reviewing any amendment to your re gistration statement and the information you
provide in response to these comments, we may have additional comments.
 Principal and Selling Stockholders, page 123

 1. We note that many of the selling stockholders are your officers, direct ors or affiliates.
Please revise your disclosure in  the section to clarify whic h of your selling stockholders
are your officers, directors or affiliates.  See Item 507 of Regulation S-K which requires
you to “indicate the nature of any position, offi ce, or other material relationship which the
selling security holder has had w ithin the past three years with the registrant or any of its
predecessors or affiliates.”
2. Please disclose whether any of the selling stockholders is a broker-dealer or an affiliate of
a broker-dealer.  If any of the selling stoc kholders are broker-dealers or affiliates of a
broker-dealer, disclose if any of the selling stockholders received these shares as
underwriting compensation.  For affiliates of a broker-dealer, please te ll us if the seller
purchased in the ordinary course of busines s; and at the time of the purchase of the
securities to be resold the seller had no  agreements or understandings, directly or

Mr. Mark S. Casady LPL Investment Holdings Inc. November 10, 2010 Page 2

indirectly, with any person to distribute the securities.  Revise your disclosure
accordingly.  We may have additional comments.
 Certain Relationships and Relate d Party Transactions, page 120

 3. We note your disclosure regarding the loans you forgave to employees becoming
executive officers of the company.  Please pr ovide all the disclosure required by Item 404
of Regulation S-K with respect to these loans.
 Underwriting, page 137

4. Please expand your conflicts of interest disclo sure to discuss any potential conflicts and
risks resulting from Goldman Sachs & Co. a nd its affiliates’ participation as selling
stockholders in the offering.

We urge all persons who are responsible for th e accuracy and adequacy of the disclosure
in the filing to be certain that the filing incl udes the information the Securities Act of 1933 and
all applicable Securities Act rules require.  Since the company and its management are in
possession of all facts relating to a company’s disc losure, they are responsible for the accuracy
and adequacy of the disclosures they have made.

Notwithstanding our comments, in the event you request acceleration of  the effective date
of the pending registration statement please pr ovide a written statement from the company
acknowledging that:
• should the Commission or the staff, acting purs uant to delegated authority, declare the
filing effective, it does not foreclose the Co mmission from taking any action with respect
to the filing;

• the action of the Commission or the staff, acting pursuant to delegated authority, in
declaring the filing effective, does not relieve the company from its full responsibility for
the adequacy and accuracy of the disclosure in the filing; and

• the company may not assert staff comments a nd the declaration of effectiveness as a
defense in any proceeding initiated by the Commission or any person under the federal
securities laws of the United States.

Please refer to Rules 460 and 461 regarding re quests for acceleration.  We will consider a
written request for acceleration of  the effective date of the regi stration statement as confirmation
of the fact that those reques ting acceleration are aware of thei r respective responsibilities under
the Securities Act of 1933 and the Securities Excha nge Act of 1934 as they relate to the proposed
public offering of the securities specified in th e above registration stat ement.  Please allow
adequate time for us to review any amendment prior to the requested effective date of the
registration statement.

Mr. Mark S. Casady LPL Investment Holdings Inc. November 10, 2010 Page 3

You may contact Howard Ef ron, Staff Accountant, at (202) 551-3439 or Kevin Woody,
Branch Chief, at (202) 551-3629 if you have que stions regarding comments on the financial
statements and related matters.  Please contac t Kristina Aberg, Attorney-Advisor, at (202) 551-
3404 or me at (202) 551-3655 with any other questions.
Sincerely,

Sonia Gupta Barros Special Counsel
 cc: Julie H. Jones, Esq.  Keith F. Higgins, Esq.  Ropes & Gray LLP