<PAGE>
                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
 
                                   FORM 10-K
(Mark One)
 
/X/ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT
    OF 1934
 
For the fiscal year ended December 31, 1998
 
                                       OR
 
/ / TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE
    ACT OF 1934
 
For the transition period from _______________________ to ______________________
 
Commission file number 333-43041
 
                         WORLD MONITOR TRUST--SERIES B
--------------------------------------------------------------------------------
             (Exact name of registrant as specified in its charter)
 
Delaware                                             13-3985041
--------------------------------------------------------------------------------
(State or other jurisdiction of           (I.R.S. Employer Identification No.)
incorporation or organization)
                                  
 
One New York Plaza, 13th Floor, New York, New York             10292
--------------------------------------------------------------------------------
(Address of principal executive offices)                     (Zip Code)
 
Registrant's telephone number, including area code: (212) 778-7866
 
Securities registered pursuant to Section 12(b) of the Act:

                                    None
------------------------------------------------------------------------------
 
Securities registered pursuant to Section 12(g) of the Act:

                              Limited Interests
------------------------------------------------------------------------------
                              (Title of class)
 
   Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days. Yes CK No __
 
   Indicate by check mark if disclosure of delinquent filers pursuant to Item
405 of Regulation S-K is not contained herein, and will not be contained, to the
best of registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K [  ]
 
                      DOCUMENTS INCORPORATED BY REFERENCE
 
   Second Amended and Restated Declaration of Trust and Trust Agreement of the
Registrant dated as of March 17, 1998, included as part of the Registration
Statement on Form S-1 (File No. 333-43041) filed with the Securities and
Exchange Commission on March 23, 1998, pursuant to Rule 424(b) of the Securities
Act of 1933, is incorporated by reference into Part IV of this Annual Report on
Form 10-K
 
   Registrant's Annual Report to Interest holders for the year ended December
31, 1998 is incorporated by reference into Parts II and IV of this Annual Report
on Form 10-K
 
                                Index to exhibits can be found on pages 8 and 9.
<PAGE>
                         WORLD MONITOR TRUST--SERIES B
                          (a Delaware Business Trust)
 
                               TABLE OF CONTENTS
<TABLE>
<CAPTION>
PART I                                                                                         PAGE
<S>        <C>                                                                                <C>
Item  1    Business.........................................................................     3
Item  2    Properties.......................................................................     4
Item  3    Legal Proceedings................................................................     4
Item  4    Submission of Matters to a Vote of Interest Holders..............................     4
 
PART II
Item  5    Market for the Registrant's Interests and Related Interest Holder Matters........     4
Item  6    Selected Financial Data..........................................................     5
Item  7    Management's Discussion and Analysis of Financial Condition and Results of
             Operations.....................................................................     5
Item 7A    Quantitative and Qualitative Disclosures About Market Risk.......................     5
Item  8    Financial Statements and Supplementary Data......................................     5
Item  9    Changes in and Disagreements with Accountants on Accounting and Financial
             Disclosure.....................................................................     5

PART III
Item 10    Directors and Executive Officers of the Registrant...............................     5
Item 11    Executive Compensation...........................................................     7
Item 12    Security Ownership of Certain Beneficial Owners and Management...................     7
Item 13    Certain Relationships and Related Transactions...................................     7
 
PART IV
Item 14    Exhibits, Financial Statement Schedules, and Reports on Form 8-K.................     8
           Financial Statements and Financial Statement Schedules...........................     8
           Exhibits.........................................................................     8
           Reports on Form 8-K..............................................................     9
 
SIGNATURES..................................................................................    10
</TABLE>
 
                                       2
<PAGE>
                                     PART I
 
Item 1. Business
 
General
 
   World Monitor Trust (the 'Trust') is a business trust organized under the
laws of Delaware on December 17, 1997. The Trust commenced trading operations on
June 10, 1998 and will terminate on December 31, 2047 unless terminated sooner
as provided in the Second Amended and Restated Declaration of Trust and Trust
Agreement (the 'Trust Agreement'). The Trust was formed to engage in the
speculative trading of a diversified portfolio of futures, forward and options
contracts and may, from time to time, engage in cash and spot transactions. The
trustee of the Trust is Wilmington Trust Company. The Trust's fiscal year for
book and tax purposes ends on December 31.
 
The Offering
 
   Beneficial interests in the Trust ('Interests') are being offered pursuant to
Rule 415 of Regulation C under the Securities Act of 1933 in three separate and
distinct series ('Series'): Series A, B and C. The assets of each Series are
segregated from the other Series, separately valued and independently managed.
 
   Up to $100,000,000 of Interests ('Subscription Maximum'), $34,000,000 for
Series A and $33,000,000 each for Series B and C, are being offered to investors
who meet certain established suitability standards. A subscriber may purchase
Interests in any one or a combination of Series. On June 10, 1998, Series B (the
'Registrant') completed its initial offering with gross proceeds of $5,709,093
from the sale of 56,330.929 limited interests and 760 general interests.
 
   Thereafter, or until the Subscription Maximum for each Series is sold, each
Series' Interests will continue to be offered on a weekly basis ('Continuous
Offering Period') at the net asset value per Interest.
 
   The Registrant is engaged solely in the business of commodity futures and
forward trading; therefore, presentation of industry segment information is not
applicable.
 
Managing Owner
 
   The managing owner of the Registrant is Prudential Securities Futures
Management Inc. (the 'Managing Owner'), a wholly owned subsidiary of Prudential
Securities Incorporated ('PSI') which, in turn, is a wholly owned subsidiary of
Prudential Securities Group Inc. PSI is the selling agent for the Registrant as
well as the commodity broker of the Registrant. The Managing Owner is required
to maintain at least a 1% interest in the capital, profits and losses of each
Series so long as it is acting as the Managing Owner, and it will make such
contributions (and in return will receive such general interests) as are
necessary to effect this requirement.
 
The Trading Advisor
 
   Each Series has its own independent commodity trading advisor that makes that
Series' trading decisions. The Managing Owner, on behalf of the Registrant,
entered into an advisory agreement with Eclipse Capital Management, Inc. (the
'Trading Advisor') to make the trading decisions for Series B. The advisory
agreement may be terminated at the discretion of the Managing Owner. The
Managing Owner has allocated 100% of the proceeds from the initial and
continuous offering of Series B to the Trading Advisor and it is currently
contemplated that the Trading Advisor will continue to be allocated 100% of
additional capital raised for Series B during the Continuous Offering Period.
 
Competition
 
   The Managing Owner and its affiliates have formed, and may continue to form,
various entities to engage in the speculative trading of futures, forward and
options contracts which have certain of the same investment policies as the
Registrant.
 
   The Registrant is an open-end fund which will solicit the sale of additional
Interests on a weekly basis until the Subscription Maximum is reached. As such,
the Registrant may compete with other entities to attract new participants. In
addition, to the extent that the Trading Advisor recommends similar or identical
trades
 
                                       3
<PAGE>
to the Registrant and other accounts which it manages, the Registrant may
compete with those accounts for the execution of the same or similar trades.
 
Employees
 
   The Registrant has no employees. Management and administrative services for
the Registrant are performed by the Managing Owner and its affiliates pursuant
to the Trust Agreement as further discussed in Notes A, C and D to the
Registrant's annual report to limited owners for the year ended December 31,
1998 (the 'Registrant's 1998 Annual Report') which is filed as an exhibit
hereto.
 
Item 2. Properties
 
   The Registrant does not own or lease any property.
 
Item 3. Legal Proceedings
 
   There are no material legal proceedings pending by or against the Registrant
or the Managing Owner.
 
Item 4. Submission of Matters to a Vote of Interest Holders
 
   None
 
                                    PART II
 
Item 5. Market for the Registrant's Interests and Related Interest Holder
        Matters
 
   Information with respect to the offering of Interests is incorporated by
reference to Note A to the Registrant's 1998 Annual Report, which is filed as an
exhibit hereto.
 
   A significant secondary market for the Interests has not developed, and it is
not expected that one will develop in the future. There are also certain
restrictions set forth in the Trust Agreement limiting the ability of an
Interest holder to transfer Interests. However, Interests may be redeemed on a
weekly basis, but are subject to a redemption fee if effected within one year of
the effective date of purchase. Additionally, Interests owned in one Series may
be exchanged, without any charge, for Interests of one or more other Series on a
weekly basis for as long as Interests in those Series are being offered to the
public. Exchanges and redemptions are calculated based on the applicable Series'
then current net asset value per Interest as of the close of business on the
Friday immediately preceding the week in which the exchange or redemption
request is effected.
 
   There are no material restrictions upon the Registrant's present or future
ability to make distributions in accordance with the provisions of the Trust
Agreement. No distributions have been made since inception and no distributions
are anticipated in the future.
 
   As of March 4, 1999, there were 1,088 holders of record owning 124,937.463
Interests which include 1,350 general interests.
 
                                       4
<PAGE>
Item 6. Selected Financial Data
 
   The following table presents selected financial data of the Registrant for
the period from June 10, 1998 (commencement of operations) to December 31, 1998.
This data should be read in conjunction with the financial statements of the
Registrant and the notes thereto on pages 2 through 9 of the Registrant's 1998
Annual Report which is filed as an exhibit hereto.
 
<TABLE>
<S>                                                                    <C>
Total revenues (including interest)                                            $  1,732,093
                                                                           ----------------
                                                                           ----------------
Net income                                                                     $  1,059,653
                                                                           ----------------
                                                                           ----------------
Net income per weighted average Interest                                       $      13.06
                                                                           ----------------
                                                                           ----------------
Total assets                                                                   $ 11,558,059
                                                                           ----------------
                                                                           ----------------
Net asset value per Interest                                                   $     111.98
                                                                           ----------------
                                                                           ----------------
</TABLE>
 
Item 7. Management's Discussion and Analysis of Financial Condition and Results
        of Operations
 
   This information is incorporated by reference to pages 10 through 12 of the
Registrant's 1998 Annual Report which is filed as an exhibit hereto.
 
Item 7A. Quantitative and Qualitative Disclosures About Market Risk
 
   Information regarding quantitative and qualitative disclosures about market
risk is not required pursuant to Item 305(e) of Regulation S-K.
 
Item 8. Financial Statements and Supplementary Data
 
   The financial statements are incorporated by reference to pages 2 through 9
of the Registrant's 1998 Annual Report which is filed as an exhibit hereto.
 
   Supplementary data specified by Item 302 of Regulation S-K (selected
quarterly financial data) is not applicable.
 
Item 9. Changes in and Disagreements with Accountants on Accounting and
        Financial Disclosure
 
   None
 
                                    PART III
 
Item 10. Directors and Executive Officers of the Registrant
 
   There are no directors or executive officers of the Registrant. The
Registrant is managed by the Managing Owner.
 
   The Managing Owner's directors and executive officers and any person holding
more than ten percent of the Registrant's Interests ('Ten Percent Owners') are
required to report their initial ownership of such Interests and any subsequent
changes in that ownership to the Securities and Exchange Commission on Forms 3,
4 or 5. Such executive officers, directors and Ten Percent Owners are required
by Securities and Exchange Commission regulations to furnish the Registrant with
copies of all Forms 3, 4 or 5 they file. Tamara B. Wright, upon becoming a
director, and the Massachusetts Bay Transportation Authority Retirement Fund,
upon becoming a Ten Percent Owner, did not file Form 3 in a timely manner, but
have subsequently filed and are now current in all filings. All other filing
requirements were satisfied on a timely basis. In making these disclosures, the
Registrant has relied solely on written representations of the Managing Owner's
directors and executive officers and Ten Percent Owners or copies of the reports
that they have filed with the Securities and Exchange Commission during and with
respect to its most recent fiscal year.
 
                                       5
 <PAGE>
<PAGE>
   The directors and executive officers of Prudential Securities Futures
Management Inc. and their positions with respect to the Registrant are as
follows:
 
          Name                                      Position
Eleanor L. Thomas            First Vice President
Barbara J. Brooks            Chief Financial Officer
Steven Carlino               Vice President, Chief Accounting Officer 
                               and Treasurer
A. Laurence Norton, Jr.      Director
Guy S. Scarpaci              Director
Tamara B. Wright             Senior Vice President and Director
 
   ELEANOR L. THOMAS, age 44, has been a Vice President of Prudential Securities
Futures Management Inc. and Seaport Futures Management, Inc. since April 1993
and a First Vice President since October 1998. She is primarily responsible for
origination, asset allocation, and due diligence for the managed futures group
within PSI. She is also a First Vice President of PSI. Prior to joining PSI in
March 1993, she was with MC Baldwin Financial Company from June 1990 through
February 1993 and Arthur Anderson & Co. from 1986 through May 1990. Ms. Thomas
is a certified public accountant.
 
   BARBARA J. BROOKS, age 50, is the Chief Financial Officer of Prudential
Securities Futures Management Inc. She is a Senior Vice President of PSI. She is
also the Chief Financial Officer of Seaport Futures Management, Inc. and serves
in various capacities for other affiliated companies. She has held several
positions within PSI since April 1983. Ms. Brooks is a certified public
accountant.
 
   STEVEN CARLINO, age 35, is a Vice President and Treasurer of Prudential
Securities Futures Management Inc. He is a First Vice President of PSI. He is
also a Vice President and Treasurer of Seaport Futures Management, Inc. and
serves in various capacities for other affiliated companies. Prior to joining
PSI in October 1992, he was with Ernst & Young for six years. Mr. Carlino is a
certified public accountant.
 
  A. LAURENCE NORTON, JR., age 60, is a Director of Prudential Securities
Futures Management Inc. He is an Executive Vice President of PSI and, since
March 1994, has been the head of the International and Futures Divisions of PSI.
He is also a Director of Seaport Futures Management, Inc. From October 1991 to
March 1994, he held the position of Executive Director of Retail Development and
Retail Strategies at PSI. Prior to joining PSI in 1991, Mr. Norton was a Senior
Vice President and Branch Manager of Shearson Lehman Brothers.
 
  GUY S. SCARPACI, age 52, is a Director of Prudential Securities Futures
Management Inc. He is a First Vice President of the Futures Division of PSI. He
is also a Director of Seaport Futures Management, Inc. Mr. Scarpaci has been
employed by PSI in positions of increasing responsibility since August 1974.
 
  TAMARA B. WRIGHT, age 40, is a Director and a Senior Vice President of
Prudential Securities Futures Management Inc. She is a Senior Vice President and
Chief Administrative Officer for the International and Futures Divisions of PSI.
She is also a Director and a Senior Vice President of Seaport Futures
Management, Inc. and serves in various capacities for other affiliated
companies. Prior to joining PSI in July 1988, she was a manager with Price
Waterhouse.
 
  During the fourth quarter of 1998, Steven Carlino replaced Barbara J. Brooks
as Treasurer of Prudential Securities Futures Management Inc. and Seaport
Futures Management, Inc. Additionally during December 1998, Tamara B. Wright was
elected as a Senior Vice President and Director of Prudential Securities Futures
Management Inc. and Seaport Futures Management, Inc. On March 26, 1999, Thomas
M. Lane, Jr. resigned as President and Director of Prudential Securities Futures
Management Inc. and Seaport Futures Management, Inc.
 
  There are no family relationships among any of the foregoing directors or
executive officers. All of the foregoing directors and/or executive officers
have indefinite terms.
 
                                       6
<PAGE>
Item 11. Executive Compensation
 
   The Registrant does not pay or accrue any fees, salaries or any other form of
compensation to directors and officers of the Managing Owner for their services.
Certain directors and officers of the Managing Owner receive compensation from
affiliates of the Managing Owner, not from the Registrant, for services
performed for various affiliated entities, which may include services performed
for the Registrant; however, the Managing Owner believes that any compensation
attributable to services performed for the Registrant is immaterial. (See also
Item 13, Certain Relationships and Related Transactions, for information
regarding compensation to the Managing Owner.)
 
Item 12. Security Ownership of Certain Beneficial Owners and Management
 
   As of March 4, 1999, no director or executive officer of the Managing Owner
owns directly or beneficially any interest in the voting securities of the
Managing Owner.
 
   As of March 4, 1999, no director or executive officer of the Managing Owner
owns directly or beneficially any of the Interests issued by the Registrant.
 
   As of March 4, 1999, the following owner of limited interests beneficially
owns more than five percent (5%) of the limited interests issued by the
Registrant:
 
<TABLE>
<CAPTION>
      Title                  Name and Address of               Amount and Nature of         Percent of
     of Class                 Beneficial Owner                 Beneficial Ownership           Class
------------------    ---------------------------------    -----------------------------    ----------
<S>                   <C>                                  <C>                              <C>
Limited interests     Massachusetts Bay Transportation      17,666.743 limited interests           14%
                      Authority Retirement Fund
                      99 Summer Street, 17th Floor
                      Boston, MA 02110-1200
</TABLE>
 
Item 13. Certain Relationships and Related Transactions
 
   The Registrant has and will continue to have certain relationships with the
Managing Owner and its affiliates. However, there have been no direct financial
transactions between the Registrant and the directors or officers of the
Managing Owner.
 
   Reference is made to Notes A, C and D to the financial statements in the
Registrant's 1998 Annual Report which is filed as an exhibit hereto, which
identify the related parties and discuss the services provided by these parties
and the amounts paid or payable for their services.
 
                                       7
 <PAGE>
<PAGE>
                                    PART IV
 
<TABLE>
<CAPTION>
                                                                                              Page
                                                                                             Number
                                                                                          ------------
 
<S>  <C>      <C>                                                                         <C>
Item 14. Exhibits, Financial Statement Schedules, and Reports on Form 8-K
 
(a)      1.   Financial Statements and Report of Independent Accountants--incorporated
              by reference to the Registrant's 1998 Annual Report which is filed as an
              exhibit hereto
 
              Report of Independent Accountants                                                2
 
              Financial Statements:
 
              Statements of Financial Condition--December 31, 1998 and 1997                    3
 
              Statement of Operations--Period from June 10, 1998 (commencement of
              operations) to December 31, 1998                                                 4
 
              Statement of Changes in Trust Capital--Year ended December 31, 1998              4
 
              Notes to Financial Statements                                                    5
 
         2.   Financial Statement Schedules
 
              All schedules have been omitted because they are not applicable or the
              required information is included in the financial statements or notes
              thereto.
 
         3.   Exhibits
 
              Description:
 
        3.1   Second Amended and Restated Declaration of Trust and Trust Agreement of
        and   World Monitor Trust dated as of March 17, 1998 (incorporated by reference
        4.1   to Exhibits 3.1 and 4.1 to Series B's Registration Statement on Form S-1,
              File No. 333-43041, dated as of March 23, 1998)
 
        4.2   Form of Request for Redemption (incorporated by reference to Exhibit 4.2
              to Series B's Registration Statement on Form S-1, File No. 333-43041,
              dated as of March 23, 1998)
 
        4.3   Form of Exchange Request (incorporated by reference to Exhibit 4.3 to
              Series B's Registration Statement on Form S-1, File No. 333-43041, dated
              as of March 23, 1998)
 
        4.4   Form of Subscription Agreement (incorporated by reference to Exhibit 4.4
              to Series B's Registration Statement on Form S-1, File No. 333-43041,
              dated as of March 23, 1998)
 
       10.1   Form of Escrow Agreement among the Trust, Prudential Securities Futures
              Management Inc., Prudential Securities Incorporated and The Bank of New
              York (incorporated by reference to Exhibit 10.1 to Series B's
              Registration Statement on Form S-1, File No. 333-43041, dated as of March
              23, 1998)
 
       10.2   Form of Brokerage Agreement between the Trust and Prudential Securities
              Incorporated (incorporated by reference to Exhibit 10.2 to Series B's
              Registration Statement on Form S-1, File No. 333-43041, dated as of March
              23, 1998)
 
       10.3   Form of Advisory Agreement among the Registrant, Prudential Securities
              Futures Management Inc., and the Trading Advisor (incorporated by
              reference to Exhibit 10.3 to Series B's Registration Statement on Form
              S-1, File No. 333-43041, dated as of March 23, 1998)
</TABLE>
 
                                       8
<PAGE>
<TABLE>
<S>  <C>      <C>                                                                         <C>
       10.4   Form of Representation Agreement Concerning the Registration Statement
              and the Prospectus among the Registrant, Prudential Securities Futures
              Management Inc., Prudential Securities Incorporated, Wilmington Trust
              Company and the Trading Advisor (incorporated by reference to Exhibit
              10.4 to Series B's Registration Statement on Form S-1, File No.
              333-43041, dated as of March 23, 1998)
 
       10.5   Form of Net Worth Agreement between Prudential Securities Futures
              Management Inc. and Prudential Securities Group Inc. (incorporated by
              reference to Exhibit 10.5 to Series B's Registration Statement on Form
              S-1, File No. 333-43041, dated as of March 23, 1998)
 
       10.6   Form of Foreign Currency Addendum to Brokerage Agreement between the
              Trust and Prudential Securities Incorporated (incorporated by reference
              to Exhibit 10.6 to Series B's Quarterly Report on Form 10-Q, File No.
              333-43041, for the quarter ended March 31, 1998)
 
       13.1   Registrant's 1998 Annual Report (with the exception of the information
              and data incorporated by reference in Items 5, 7 and 8 of this Annual
              Report on Form 10-K, no other information or data appearing in the
              Registrant's 1998 Annual Report is to be deemed filed as part of this
              report) (filed herewith)
 
       27.1   Financial Data Schedule (filed herewith)
 
(b)           Reports on Form 8-K
 
              No reports on Form 8-K were filed during the last quarter of the period
              covered by this report.
</TABLE>
 
                                       9
<PAGE>
                                   SIGNATURES
 
      Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the Registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized.
 
World Monitor Trust--Series B
 
By: Prudential Securities Futures Management Inc.
    A Delaware corporation, Managing Owner
 
     By: /s/ Steven Carlino                       Date: March 31, 1999
     ----------------------------------------
     Steven Carlino
     Vice President, Chief Accounting Officer
     and Treasurer
 
   Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed below by the following persons on behalf of the
Registrant and in the capacities (with respect to the Managing Owner) and on the
dates indicated.
 
By: Prudential Securities Futures Management Inc.
    A Delaware corporation, Managing Owner
 
    By: /s/ Eleanor L. Thomas                     Date: March 31, 1999
    -----------------------------------------
    Eleanor L. Thomas
    First Vice President
 
    By: /s/ Barbara J. Brooks                     Date: March 31, 1999
    -----------------------------------------
    Barbara J. Brooks
    Chief Financial Officer
 
    By: /s/ Steven Carlino                        Date: March 31, 1999
    -----------------------------------------
    Steven Carlino
    Vice President and Treasurer
 
    By:                                           Date:
    -----------------------------------------
    A. Laurence Norton, Jr.
    Director
 
    By: /s/ Guy S. Scarpaci                       Date: March 31, 1999
    -----------------------------------------
    Guy S. Scarpaci
    Director
 
    By: /s/ Tamara B. Wright                      Date: March 31, 1999
    -----------------------------------------
    Tamara B. Wright
    Senior Vice President and Director
 
                                       10