SC 13D: Schedule filed to report acquisition of beneficial ownership of 5% or more of a class of equity securities

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

UNDER THE SECURITIES AND EXCHANGE ACT OF 1934*


Chimera Investment Corp
- -------------------------------------------------------------------------------
(Name of Issuer)

Common Stock, par value of $.01 per share
- -------------------------------------------------------------------------------
(Title of Class of Securities)

16934Q109
- -------------------------------------------------------------------------------
(CUSIP Number)

Peter C. Keefe
Avenir Corporation
1919 Pennsylvania Ave NW
4th Floor
Washington DC, 20006
(202) 659-4427
- -------------------------------------------------------------------------------
(Name, Address and Telephone Number of Person
Authorized to Receive Notices and Communications)



October 21, 2008
- -------------------------------------------------------------------------------
(Date of Event Which Requires Filing of this Statement)


If the filing person has previously filed a statement on Schedule 13G to report
the acquisition which is the subject of this Schedule 13D, and is filing this
schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the
following box: [X]

NOTE: Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See Rule 240.13d-7 for other
parties to whom copies are to be sent.

*The remainder of this cover page shall be filled out for a reporting person?s
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).



SCHEDULE 13D
- ------------------ ------------------
CUSIP No. 16934Q109
- ------------------ ------------------
- ---------- ---------------------------------------------------------------------
1 NAME OF REPORTING PERSON
I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

Avenir Corporation
I.D. No. 54-1146619
- ---------- ---------------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ]
(b) [X]
- ---------- ---------------------------------------------------------------------
3 SEC USE ONLY
- ---------- ---------------------------------------------------------------------
4 SOURCE OF FUNDS*

OO
- ---------- ---------------------------------------------------------------------
5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDING IS REQUIRED PURSUANT TO
ITEMS 2(d) or 2(e) [ ]
- ---------- ---------------------------------------------------------------------
6 CITIZENSHIP OR PLACE OF ORGANIZATION

United States
- -------------------- -------- --------------------------------------------------
7 SOLE VOTING POWER

3,037,059
NUMBER -------- ---------------------------------------------------
OF SHARES 8 SHARED VOTING POWER
BENEFICIALLY
OWNED BY 0
EACH -------- ---------------------------------------------------
REPORTING 9 SOLE DISPOSITIVE POWER
PERSON WITH 3,037,059
- ---------- ---------------------------------------------------------------------
10 SHARED DISPOSITIVE POWER
- ----------- --------------------------------------------------------------------
11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH PERSON
3,037,059
- ----------- --------------------------------------------------------------------
12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
SHARES* [ ]
- ----------- --------------------------------------------------------------------
13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

7.8%
- ----------- --------------------------------------------------------------------
14 TYPE OF REPORTING PERSON*

IA
- ----------- --------------------------------------------------------------------


SCHEDULE 13D
- ------------------ ------------------
CUSIP No. 16934Q109
- ------------------ ------------------
This Schedule 13D ("Schedule") is being filed on behalf of Avenir Corporation
("Avenir"), a Virginia corporation and amends the Schedule 13G filed
on June 10, 2008 on behalf of Avenir. This Schedule relates to the common
stock, par value $0.01 per share, of Chimera Investment Corp, a Maryland
corporation (the "Issuer"). Unless the context otherwise requires, references
herein to "Securities" or "Shares" are to such common stock of the Issuer.

Item 3. Source and Amount of Funds or Other Consideration.

The Securities of the Issuer were primarily acquired on behalf of the
investment advisory clients of Avenir under sole or shared discretionary
authority granted Avenir. In addition, Avenir and/or its principal officers
and employees purchased Shares in the Issuer for their personal accounts. The
aggregate amount of funds used to purchase the Securities reported in this
filing totaled approximately $34,678,748. In addition, none of the proceeds
used to purchase the Securities were expressly provided through borrowings,
though certain accounts managed by Avenir may carry margin balances from time
to time.

Item 5. Interest In Securities Of The Issuer

(a) The aggregate number and percentage of Securities to which this
Schedule 13D relates is 3,037,059 shares of the common stock of the Issuer,
constituting approximately 7.8% of the 38,999,850 shares outstanding.

(b) Avenir generally has the sole power to dispose of or to direct the
disposition of the Securities held for discretionary accounts of its investment
clients, and may be granted the sole power to vote or direct the vote of such
Securities; such powers may be retained by or shared with the respective clients
for shared or non-discretionary accounts, for which Avenir generally makes
recommendations with respect thereto.

(c) All purchase or sale transactions in the Securities during the
past sixty days are set forth on Schedule A.

(d) The investment advisory clients of Avenir have the sole right to
receive and, subject to notice, to withdraw the proceeds from the sale of the
Securities, and the sole power to direct the receipt of dividends from any of
the Securities held for their respective accounts. Such clients may also
terminate the investment advisory agreements without penalty upon appropriate
notice.

(e) Not applicable.

Item 6. Contracts, Arrangements, Understandings or Relationships with Respect
to Securities of the Issuer

The powers of disposition with respect to Securities owned by discretionary
private accounts of Avenir are established in written investment advisory
agreements between clients and Avenir, which are entered into in the normal
and usual course of the business of Avenir as a registered investment advisor
and which are generally applicable to all securities purchased for the benefit
of each such discretionary private account. There are no special or different
agreements relating to the Securities of the Issuer.

The written investment advisory agreements with clients do not contain
provisions relating to borrowing of funds to finance the acquisition of the
Securities, acquisition of control, transfer of securities, joint ventures,
or any of the other transactions listed in the instructions to Item 7 of
Schedule 13D other than voting of proxies. In connection with voting, Avenir
may be allowed or directed to vote the proxies received by accounts classified
as "discretionary" or "shared" accounts; such authority is generally retained
by the clients for accounts classified as "non-discretionary".

Item 7. Material to be Filed as an Exhibit







SCHEDULE 13D
- ------------------ ------------------
CUSIP No. 16934Q109
- ------------------ ------------------

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.


October 21, 2008
-----------------------------------
Date

/s/ Peter C. Keefe
-----------------------------------
Signature

Peter C. Keefe, President
-----------------------------------
Name/Title














SCHEDULE 13D
- ------------------ ------------------
CUSIP No. 16934Q109
- ------------------ ------------------

SCHEDULE A


PURCHASE ("BY") AND SALE ("SL") TRANSACTIONS WITHIN PAST 60 DAYS

All purchases and sales listed below were normal, open-market transactions.