nq2.htm



 
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, DC 20549

FORM N-Q

QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED MANAGEMENT INVESTMENT COMPANY
 
Investment Company Act file number 811-22425
 
Nuveen Build America Bond Opportunity Fund
(Exact name of registrant as specified in charter)
 
Nuveen Investments
        333 West Wacker Drive, Chicago, Illinois 60606         
(Address of principal executive offices) (Zip code)
 

Kevin J. McCarthy
Vice President and Secretary
        333 West Wacker Drive, Chicago, Illinois 60606         
(Name and address of agent for service)
 
Registrant's telephone number, including area code:         312-917-7700        
 
Date of fiscal year end:            3/31          
 
Date of reporting period:         12/31/10         
 
Form N-Q is to be used by management investment companies, other than small business investment companies registered on Form N-5 (§§ 239.24 and 274.5 of this chapter), to file reports with the Commission, not later than 60 days after the close of the first and third fiscal quarters, pursuant to rule 30b1-5 under the Investment Company Act of 1940 (17 CFR 270.30b1-5). The Commission may use the information provided on Form N-Q in its regulatory, disclosure review, inspection, and policymaking roles.
 
A registrant is required to disclose the information specified by Form N-Q, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-Q unless the Form displays a currently valid Office of Management and Budget ("OMB") control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to the Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. § 3507.

 
 
 

 
Item 1. Schedule of Investments
 
 

           
   
Portfolio of Investments (Unaudited) 
     
   
   Nuveen Build America Bond Opportunity Fund (NBD) 
     
   
   December 31, 2010 
     
Principal 
   
Optional Call 
   
Amount (000) 
 
Description (1) 
Provisions (2) 
Ratings (3) 
Value 
   
Arizona – 1.3% (1.2% of Total Investments) 
     
$ 2,000 
 
Salt River Project Agricultural Improvement and Power District, Arizona, Electric System 
No Opt. Call 
Aa1 
$ 1,845,360 
   
Revenue Bonds, Build America Bonds, Series 2010A, 4.839%, 1/01/41 
     
   
California – 11.9% (10.7% of Total Investments) 
     
1,030 
 
Bay Area Toll Authority, California, Revenue Bonds, San Francisco Bay Area Toll Bridge, 
No Opt. Call 
A+ 
1,051,115 
   
Subordinate Lien, Build America Federally Taxable Bond Series 2010S-1, 7.043%, 4/01/50 
     
1,500 
 
California State Public Works Board, Lease Revenue Bonds, Various Capital Projects, Build 
No Opt. Call 
A2 
1,513,785 
   
America Taxable Bond Series 2009G-2, 8.361%, 10/01/34 
     
2,000 
 
Hayward Unified School District, Alameda County, California, General Obligation Bonds, Build 
8/20 at 100.00 
AA+ 
2,038,320 
   
America Taxable Bonds, Series 2010B, 7.350%, 8/01/43 – AGM Insured 
     
2,000 
 
Los Angeles Community College District, Los Angeles County, California, General Obligation 
No Opt. Call 
Aa1 
2,400,800 
   
Bonds, Tender Option Bond Trust TN027, 29.762%, 8/01/49 (IF) (4) 
     
1,000 
 
Los Angeles County Public Works Financing Authority, California, Lease Revenue Bonds, Mulitple 
No Opt. Call 
A+ 
992,700 
   
Capital Projects I, Build America Taxable Bond Series 2010B, 7.618%, 8/01/40 
     
2,000 
 
Los Angeles Department of Water and Power, California, Water System Revenue Bonds, Tender 
No Opt. Call 
AA+ 
2,424,400 
   
Option Bond Trust T0003, 29.407%, 7/01/42 (IF) 
     
1,500 
 
San Diego County Regional Transportation Commission, California, Sales Tax Revenue Bonds, 
No Opt. Call 
AAA 
1,468,680 
   
Build America Taxable Bonds Series 2010A, 5.911%, 4/01/48 
     
2,000 
 
San Francisco City and County, California, Certificates of Participation, 525 Golden Gate Avenue, 
No Opt. Call 
AA– 
1,609,500 
   
San Francisco Public Utilities Commission Office Project, Tender Option Bond Trust B001, 
     
   
29.163%, 11/01/41 (IF) 
     
3,000 
 
The Regents of the University of California, Medical Center Pooled Revenue Bonds, Build 
No Opt. Call 
Aa2 
2,960,940 
   
America Taxable Bonds, Series 2010H, 6.548%, 5/15/48 
     
16,030 
 
Total California 
   
16,460,240 
   
Colorado – 4.4% (4.0% of Total Investments) 
     
4,000 
 
Colorado State Bridge Enterprise Revenue Bonds, Federally Taxable Build America Series 2010A, 
No Opt. Call 
AA 
4,099,240 
   
6.078%, 12/01/40 
     
2,000 
 
Regional Transportation District, Colorado, Sales Tax Revenue Bonds, FasTracks Project, Build 
No Opt. Call 
AA+ 
2,013,440 
   
America Series 2010B, 5.844%, 11/01/50 
     
6,000 
 
Total Colorado 
   
6,112,680 
   
Connecticut – 1.2% (1.1% of Total Investments) 
     
1,500 
 
Harbor Point Infrastructure Improvement District, Connecticut, Special Obligation Revenue 
4/20 at 100.00 
N/R 
1,623,420 
   
Bonds, Harbor Point Project, Federally Taxable – Issuer Subsidy – Recovery Zone Economic 
     
   
Development Bond Series 2010B, 12.500%, 4/01/39 
     
   
District of Columbia – 2.8% (2.5% of Total Investments) 
     
800 
 
District of Columbia, Income Tax Secured Revenue Bonds, Build America Taxable Bonds, Series 
No Opt. Call 
AAA 
812,784 
   
2009E, 5.591%, 12/01/34 
     
3,000 
 
District of Columbia, Income Tax Secured Revenue Bonds, Build America Taxable Bonds, Series 
No Opt. Call 
AAA 
3,069,990 
   
2010F, 5.582%, 12/01/35 (4) 
     
3,800 
 
Total District of Columbia 
   
3,882,774 
   
Georgia – 3.4% (3.1% of Total Investments) 
     
2,000 
 
Georgia Municipal Electric Authority, Plant Vogtle Units 3 & 4 Project J Bonds, Taxable Build 
No Opt. Call 
A+ 
1,970,580 
   
America Bonds Series 2010A, 6.637%, 4/01/57 
     
3,000 
 
Georgia Municipal Electric Authority, Plant Vogtle Units 3 & 4 Project P Bonds, Refunding 
No Opt. Call 
A– 
2,775,900 
   
Taxable Build America Bonds Series 2010A, 7.055%, 4/01/57 
     
5,000 
 
Total Georgia 
   
4,746,480 
   
Illinois – 12.1% (10.9% of Total Investments) 
     
3,375 
 
Chicago Transit Authority, Illinois, Sales Tax Receipts Revenue Bonds, Federally Taxable Build 
No Opt. Call 
AA 
3,107,599 
   
America Bonds, Series 2010B, 6.200%, 12/01/40 
     
4,350 
 
Chicago, Illinois, Wastewater Transmission Revenue Bonds, Build America Taxable Bond Series 
No Opt. Call 
Aa3 
4,382,712 
   
2010B, 6.900%, 1/01/40 
     
2,000 
 
Illinois State, General Obligation Bonds, Build America Taxable Bonds, Series 2010-5, 
No Opt. Call 
A+ 
1,968,780 
   
7.350%, 7/01/35 
     
2,720 
 
Illinois Toll Highway Authority, Toll Highway Revenue Bonds, Build America Taxable Bonds, 
No Opt. Call 
AA– 
2,685,184 
   
Senior Lien Series 2009A, 6.184%, 1/01/34 
     
2,500 
 
Northern Illinois Municipal Power Agency, Power Project Revenue Bonds, Prairie State Project, 
No Opt. Call 
A2 
2,532,850 
   
Build America Taxable Bond Series 2010A, 7.820%, 1/01/40 
     
2,000 
 
The Board of Trustee of Northern Illinois University, Auxiliary Facilities System Revenue 
4/20 at 100.00 
Aa3 
2,064,960 
   
BondsFederally Taxable Build America Series 2010, 7.947%, 4/01/35 – AGM Insured 
     
16,945 
 
Total Illinois 
   
16,742,085 
   
Indiana – 1.9% (1.7% of Total Investments) 
     
2,500 
 
Indianapolis Local Public Improvement Bond Bank, Indiana, Build America Taxable Bonds, Series 
No Opt. Call 
AA+ 
2,626,925 
   
2010B-2, 6.116%, 1/15/40 
     
   
Kentucky – 2.2% (2.0% of Total Investments) 
     
3,000 
 
Louisville and Jefferson County Metropolitan Sewer District, Kentucky, Sewer and Drainage 
No Opt. Call 
AA– 
3,020,580 
   
System Revenue Bonds, Build America Taxable Bonds Series 2010A, 6.250%, 5/15/43 
     
   
Massachusetts – 1.9% (1.8% of Total Investments) 
     
2,000 
 
Massachusetts, Transportation Fund Revenue Bonds, Accelerated Bridge Program, Tender Option 
No Opt. Call 
Aaa 
2,684,900 
   
Bond Trust T0004, 25.356%, 6/01/40 (IF) 
     
   
Michigan – 6.8% (6.2% of Total Investments) 
     
3,000 
 
Detroit City School District, Wayne County, Michigan, General Obligation Bonds, Build America 
5/20 at 100.00 
Aa2 
2,920,170 
   
Taxable Bond Series 2010B, 6.845%, 5/01/40 
     
3,000 
 
Grand Rapids, Michigan, Sanitary Sewer System Revenue Bonds, Build America Taxable Bond 
No Opt. Call 
AA+ 
2,984,670 
   
2010A, 6.720%, 1/01/41 
     
2,000 
 
Michigan Tobacco Settlement Finance Authority, Tobacco Settlement Asset-Backed Revenue Bonds, 
6/22 at 100.00 
Baa3 
1,403,260 
   
Taxable Turbo Series 2006A, 7.309%, 6/01/34 
     
2,000 
 
Wayne County Building Authority, Michigan, General Obligation Bonds, Jail Facilities, 
12/20 at 100.00 
A– 
2,111,640 
   
Federally Taxable Recovery Zone Economic Development Series 2010, 10.000%, 12/01/40 
     
10,000 
 
Total Michigan 
   
9,419,740 
   
Minnesota – 1.8% (1.7% of Total Investments) 
     
2,500 
 
Western Minnesota Municipal Power Agency, Power Supply Revenue Bonds, Build America Taxable 
No Opt. Call 
A1 
2,539,175 
   
Bond Series 2010C, 6.770%, 1/01/46 
     
   
Mississippi – 1.8% (1.6% of Total Investments) 
     
2,500 
 
Mississippi State, General Obligation Bonds, Build America Taxable Bond Series 2010F, 
No Opt. Call 
AA 
2,444,925 
   
5.245%, 11/01/34 
     
   
Missouri – 2.8% (2.5% of Total Investments) 
     
1,150 
 
Curators of the University of Missouri, System Facilities Revenue Bonds, Build America Taxable 
No Opt. Call 
AA+ 
1,206,546 
   
Bonds, Series 2010, 5.792%, 11/01/41 
     
2,500 
 
Missouri Joint Municipal Electric Utility Commission, Prairie State Power Project Revenue 
No Opt. Call 
A3 
2,663,325 
   
Bond, Federally Taxable Build America Bonds – Direct Pay, Series 2010A, 7.897%, 1/01/42 
     
3,650 
 
Total Missouri 
   
3,869,871 
   
Nevada – 1.5% (1.4% of Total Investments) 
     
2,000 
 
Washoe County, Nevada, Highway Revenue, Motor Vehicle Fuel Tax Bonds, Federally Taxable Direct 
No Opt. Call 
A+ 
2,138,020 
   
Pay Build America Bonds, Series 2010E, 7.969%, 2/01/40 
     
   
New Jersey – 5.6% (5.0% of Total Investments) 
     
3,000 
 
New Jersey Transportation Trust Fund Authority, Transportation System Bonds, Build America 
No Opt. Call 
AA– 
2,942,040 
   
Bonds Issuer Subsidy Program, Series 2010C, 5.754%, 12/15/28 
     
2,500 
 
New Jersey Turnpike Authority, Revenue Bonds, Build America Taxable Bonds, Series 2010A, 
No Opt. Call 
A+ 
2,732,800 
   
7.102%, 1/01/41 
     
2,050 
 
Rutgers State University, New Jersey, Revenue Bonds, Build America Taxable Bond Series 2010H, 
No Opt. Call 
AA 
2,057,421 
   
5.665%, 5/01/40 
     
7,550 
 
Total New Jersey 
   
7,732,261 
   
New York – 15.6% (14.1% of Total Investments) 
     
10,000 
 
Dormitory Authority of the State of New York, State Personal Income Tax Revenue Bonds, Series 
No Opt. Call 
AAA 
9,678,200 
   
2010D, 5.600%, 3/15/40 (UB) 
     
2,000 
 
Metropolitan Transportation Authority, New York, Transportation Revenue Bonds, Federally 
No Opt. Call 
A
2,040,700 
   
Taxable Issuer Subsidy Build America Bonds, Series 2010A, 6.668%, 11/15/39 
     
3,000 
 
New York City Municipal Water Finance Authority, New York, Water and Sewer System Revenue 
No Opt. Call 
AA+ 
2,851,200 
   
Bonds, Second Generation Resolution, Build America Taxable Bonds, Fiscal 2011 Series 2010AA, 
     
   
5.440%, 6/15/43 
     
2,000 
 
New York City Municipal Water Finance Authority, New York, Water and Sewer System Revenue 
No Opt. Call 
AA+ 
1,930,200 
   
Bonds, Second Generation Resolution, Taxable Tender Option Bonds Trust T30001-2, 26.319%, 
     
   
6/15/44 (IF) 
     
2,455 
 
New York City Transitional Finance Authority, New York, Building Aid Revenue Bonds, Build 
No Opt. Call 
AA– 
2,550,819 
   
America Taxable Bond Fiscal 2011 Series 2010S-1B, 6.828%, 7/15/40 
     
2,500 
 
New York City, New York, General Obligation Bonds, Federally Taxable Build America Bonds, 
12/20 at 100.00 
AA 
2,564,750 
   
Series 2010-F1, 6.646%, 12/01/31 
     
21,955 
 
Total New York 
   
21,615,869 
   
North Carolina – 1.1% (1.0% of Total Investments) 
     
1,400 
 
North Carolina Turnpike Authority, Triangle Expressway System State Annual Appropriation Revenue 
1/19 at 100.00 
AA 
1,460,648 
   
Bonds, Federally Taxable Issuer Subsidy Build America Bonds, Series 2009B, 6.700%, 1/01/39 
     
   
Ohio – 4.0% (3.6% of Total Investments) 
     
2,500 
 
American Municipal Power Inc., Ohio, Meldahl Hydroelectric Projects Revenue Bonds, Federally 
No Opt. Call 
A
2,579,250 
   
Taxable Build America Bonds, Series 2010B, 7.499%, 2/15/50 
     
3,000 
 
Northeast Ohio Regional Sewer District, Wastewater Improvement Revenue Bonds, Build America 
11/20 at 100.00 
AA+ 
2,998,920 
   
Taxable Bonds, Series 2010, 6.038%, 11/15/40 
     
5,500 
 
Total Ohio 
   
5,578,170 
   
Pennsylvania – 5.7% (5.1% of Total Investments) 
     
3,000 
 
Kiski Area School District, Westmoreland County, Pennsylvania, General Obligation Bonds, Build 
9/20 at 100.00 
Aa3 
3,028,620 
   
America Taxable Bond Series 2010, 6.626%, 9/01/35 – AGM Insured 
     
2,500 
 
Pennsylvania State, General Obligation Bonds, Build America Taxable Bonds, Third Series 2010B, 
7/20 at 100.00 
Aa1 
2,567,950 
   
5.850%, 7/15/30 
     
2,500 
 
Pennsylvania Turnpike Commission, Turnpike Revenue Bonds, Build America Taxable Bonds, Series 
No Opt. Call 
Aa3 
2,273,425 
   
2010B, 5.511%, 12/01/45 
     
8,000 
 
Total Pennsylvania 
   
7,869,995 
   
Tennessee – 2.2% (2.0% of Total Investments) 
     
3,000 
 
Metropolitan Government Nashville & Davidson County Convention Center Authority, Tennesse, 
No Opt. Call 
Aa2 
3,004,740 
   
Tourism Tax Revenue Bonds, Build America Taxable Bonds, Subordinate Lien Series 2010B, 
     
   
6.731%, 7/01/43 
     
   
Texas – 7.9% (7.1% of Total Investments) 
     
1,810 
 
Board of Regents, University of Texas System, Financing System Revenue Bonds, Build America 
8/19 at 100.00 
AAA 
1,865,187 
   
Taxable Bonds, Series 2009B, 6.276%, 8/15/41 
     
2,705 
 
Dallas Area Rapid Transit, Texas, Senior Lien Sales Tax Revenue Bonds, Build America Taxable 
No Opt. Call 
AA+ 
2,846,688 
   
Bonds, Series 2009B, 5.999%, 12/01/44 
     
2,000 
 
Dallas Convention Center Hotel Development Corporation, Texas, Hotel Revenue Bonds, Build 
No Opt. Call 
A+ 
2,020,900 
   
America Taxable Bonds, Series 09B, 7.088%, 1/01/42 
     
2,500 
 
Dallas Independent School District, Dallas County, Texas, General Obligation Bonds, School 
2/21 at 100.00 
AAA 
2,617,050 
   
Building, Build America Taxable Bond Series 2010C, 6.450%, 2/15/35 
     
1,500 
 
North Texas Tollway Authority, System Revenue Bonds, Subordinate Lien Taxable Revenue Bonds, 
2/20 at 100.00 
Baa3 
1,548,705 
   
Federally Taxable Build America Bonds, Series 2010-B2, 8.910%, 2/01/30 
     
10,515 
 
Total Texas 
   
10,898,530 
   
Virginia – 1.3% (1.2% of Total Investments) 
     
3,000 
 
Tobacco Settlement Financing Corporation of Virginia, Tobacco Settlement Asset Backed Bonds, 
6/12 at 100.00 
Baa3 
1,846,410 
   
Refunding Senior Lien Series 2007A1, 6.706%, 6/01/46 
     
   
Washington – 1.8% (1.6% of Total Investments) 
     
1,000 
 
Washington State Convention Center Public Facilities District, Lodging Tax Revenue Bonds, 
No Opt. Call 
Aa3 
998,730 
   
Build America Taxable Bond Series 2010B, 6.790%, 7/01/40 
     
1,500 
 
Washington State Economic Development Finance Authority, Biomedical Research Properties Lease 
No Opt. Call 
AA+ 
1,495,814 
   
Revenue Bonds, BuilAmerica Series 2010, 6.516%, 7/01/42 
     
2,500 
 
Total Washington 
   
2,494,544 
$ 142,845 
 
Total Long-Term Investments (cost $140,371,813) – 103.0% 
   
142,658,342 
           
   
Short-Term Investments – 7.6% (6.9% of Total Investments) 
     
   
South Carolina – 7.6% (6.9% of Total Investments) 
     
$   10,000 
 
South Carolina Public Service Authority, Electric System Revenue Bonds, Santee Cooper, 
No Opt. Call 
Aa2 
10,555,800 
   
Variable Rate Demand Obligations, Build America Taxable Series 2010C, 
     
   
6.454%, 1/01/50 (UB) (5) 
     
   
Total Short-Term Investments (cost $10,021,460) 
   
10,555,800 
   
Total Investments (cost $150,393,273) – 110.6% 
   
153,214,142 
   
Floating Rate Obligations – (11.6)% 
   
(16,000,000)
   
Other Assets Less Liabilities – 1.0% (6) 
   
1,280,284 
   
Net Assets – 100% 
   
$ 138,494,426 
 
 
 
 

 

 
 
Investments in Derivatives
 
 
Forward Swaps outstanding at December 31, 2010:
 
                 
   
Fund 
   
Fixed Rate 
   
Unrealized 
 
Notional 
Pay/Receive 
Floating Rate 
Fixed Rate 
Payment 
Effective 
Termination 
Appreciation 
Counterparty 
Amount 
Floating Rate 
Index 
(Annualized) 
Frequency 
Date (7) 
Date 
(Depreciation) 
Barclays Bank PLC 
$11,200,000 
Receive 
1-Month USD-LIBOR 
2.240% 
Monthly 
12/17/10 
12/17/15 
$ (88,949)
Morgan Stanley 
11,200,000 
Receive 
1-Month USD-LIBOR 
0.496% 
Monthly 
12/17/10 
12/17/11 
(13,690)
Morgan Stanley 
11,200,000 
Receive 
1-Month USD-LIBOR 
1.295% 
Monthly 
12/17/10 
12/17/13 
(44,500)
Morgan Stanley 
20,000,000 
Receive 
3-Month USD-LIBOR 
4.334% 
Semi-Annually 
1/12/12 
1/12/40 
2,194 
Morgan Stanley 
17,000,000 
Receive 
3-Month USD-LIBOR 
4.600% 
Semi-Annually 
1/27/12 
1/27/40 
(711,094)
Morgan Stanley 
12,000,000 
Receive 
3-Month USD-LIBOR 
4.435% 
Semi-Annually 
2/24/12 
2/24/40 
(144,452)
               
$(1,000,491)
 
 
Fair Value Measurements
 
In determining the fair value of the Fund’s investments, various inputs are used. These inputs are summarized in the three broad levels listed below:
 
 
Level 1 – Quoted prices in active markets for identical securities.
 
 
Level 2 – Other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk, etc.).
 
 
Level 3 – Significant unobservable inputs (including management’s assumptions in determining the fair value of investments).
 
 
The inputs or methodologies used for valuing securities are not an indication of the risk associated with investing in those securities. The following is a summary of the Fund’s fair value measurements as of December 31, 2010:
 
         
 
Level 1 
Level 2 
Level 3 
Total 
Investments: 
       
Municipal Bonds 
$ — 
$142,658,342 
$ — 
$142,658,342 
Short-Term Investments 
— 
10,555,800 
— 
10,555,800 
Derivatives: 
       
Forward Swaps* 
— 
(1,000,491)
— 
(1,000,491)
Total 
$ — 
$152,213,651 
$ — 
$152,213,651 
* Represents net unrealized appreciation (depreciation). 
       
 
During the period ended December 31, 2010, the Fund recognized no significant transfers to/from Level 1, Level 2, or Level 3.
 
Derivative Instruments and Hedging Activities
 
The Fund records derivative instruments at fair value, with changes in fair value recognized on the Statement of Operations, when applicable. Even though the Fund’s investments in derivatives may represent economic hedges, they are not considered to be hedge transactions for financial reporting purposes.
 
 
The following table presents the fair value of all derivative instruments held by the Fund as of December 31, 2010, the location of these instruments on the Statement of Assets and Liabilities, and the primary underlying risk exposure.
 
           
   
Location on the Statement of Assets and Liabilities 
Underlying 
Derivative 
Asset Derivatives 
Liability Derivatives 
Risk Exposure 
Instrument 
Location 
Value 
  Location 
Value 
Interest Rate 
Forward Swaps 
Unrealized appreciation on 
 
  Unrealized depreciation on 
 
   
forward swaps* 
$2,194 
  forward swaps* 
$1,002,685 
* Represents cumulative unrealized appreciation (depreciation) of swap contracts as reported on the Portfolio of Investments. 
 
 
 
Income Tax Information
 
The following information is determined in accordance with income tax regulations, which may differ from accounting principles generally accepted in the United States.
 
 
At December 31, 2010, the cost of investments (excluding investments in derivates) was $134,925,419.
 
 
Gross unrealized appreciation and gross unrealized depreciation of investments (excluding investments in derivatives) at December 31, 2010, were as follows:
 
   
Gross unrealized: 
 
  Appreciation 
$ 3,630,406 
  Depreciation 
(1,341,883)
Net unrealized appreciation (depreciation) of investments 
$ 2,288,523 
 
     
(1) 
 
All percentages shown in the Portfolio of Investments are based on net assets. 
(2) 
 
Optional Call Provisions: Dates (month and year) and prices of the earliest optional call or redemption. 
   
There may be other call provisions at varying prices at later dates. Certain mortgage-backed securities 
   
may be subject to periodic principal paydowns. 
(3) 
 
Ratings: Using the highest of Standard & Poor’s Group (“Standard & Poor’s”), Moody’s Investor Service, Inc. 
   
(“Moody’s”) or Fitch, Inc. (“Fitch”) rating. Ratings below BBB by Standard & Poor’s, Baa by Moody’s or BBB 
   
by Fitch are considered to be below investment grade. Holdings designated N/R are not rated by any of 
   
these national rating agencies. 
(4) 
 
Investment, or portion of investment, has been pledged to collateralize the net payment obligations for 
   
investments in derivatives and/or inverse floating rate transactions. 
(5) 
 
Investment has a maturity of more than one year, but has variable rate and demand features which qualify 
   
it as a short-term investment. The rate disclosed is that in effect at the end of the reporting period. This rate 
   
changes periodically based on market conditions or a specified market index. 
(6) 
 
Other Assets Less Liabilities includes Value and/or Unrealized Appreciation (Depreciation) of derivative 
   
instruments as noted in Investments in Derivatives. 
(7) 
 
Effective date represents the date on which both the Fund and Counterparty commence interest payment 
   
accruals on each forward swap contract. 
N/R 
 
Not rated. 
(IF) 
 
Inverse floating rate investment. 
(UB) 
 
Underlying bond of an inverse floating rate trust reflected as a financing transaction. 
USD-LIBOR 
 
United States Dollar-London Inter-Bank Offered Rate. 
 
 
 
 
 

 
Item 2. Controls and Procedures.

a.  
The registrant's principal executive and principal financial officers, or persons performing similar functions, have concluded that the registrant's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the "1940 Act") (17 CFR 270.30a-3(c))) are effective, as of a date within 90 days of the filing date of this report that includes the disclosure required by this paragraph, based on their evaluation of the controls and procedures required by Rule 30a-3(b) under the 1940 Act (17 CFR 270.30a-3(b)) and Rule 13a-15(b) or 15d-15(b) under the Securities Exchange Act of 1934 (17 CFR 240.13a-15(b) or 240.15d-15(b)).
 
 
b.  
There were no changes in the registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act (17 CFR 270.30a-3(d)) that occurred during the registrant's last fiscal quarter that have materially affected, or are reasonably likely to materially affect, the registrant's internal control over financial reporting.
 
Item 3. Exhibits.

File as exhibits as part of this Form a separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the 1940 Act (17 CFR 270.30a-2(a)), exactly as set forth below: See EX-99 CERT attached hereto.

 
 
 

 
SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.
 
(Registrant)  Nuveen Build America Bond Opportunity Fund 
 
By (Signature and Title)     /s/ Kevin J. McCarthy                    
                                                   Kevin J. McCarthy
                                                   Vice President and Secretary
 
Date         March 1, 2011        
 
Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.
 
By (Signature and Title)     /s/ Gifford R. Zimmerman                    
                                                    Gifford R. Zimmerman
                                                  Chief Administrative Officer (principal executive officer) 
 
Date         March 1, 2011        
 
By (Signature and Title)     /s/ Stephen D. Foy                              
                                                   Stephen D. Foy
                                                  Vice President and Controller (principal financial officer) 
 
Date         March 1, 2011