<PAGE>
THE MUNDER FUNDS
SUPPLEMENT DATED DECEMBER 21, 1998
TO PROSPECTUS DATED OCTOBER 27, 1998
CLASS A, B, C SHARES OF:
THE MUNDER EQUITY SELECTION FUND
FUND INFORMATION
The "FUND INFORMATION--Goal and Principal Investments" section in the Prospectus
is deleted in its entirety and supplemented as follows:
GOAL AND PRINCIPAL INVESTMENTS. The Fund's goal is to provide long-term
capital appreciation.
- - Under normal market conditions, the Fund will invest at least 65% of its
assets in Equity Securities. "Equity Securities" include common stocks,
preferred stocks, warrants and other securities convertible into common
stock, including convertible bonds and convertible preferred stock.
- - The Advisor's dedicated research team invests the Fund's assets in Equity
Securities which it believes are undervalued compared to stocks of other
companies in the same industry.
- - The Fund generally invests in issuers with market capitalizations of at
least $1 billion.
- - The Fund diversifies its assets by industry in approximately the same
weightings as those of the Standard & Poor's 500 Composite Stock Price
Index ("S&P 500").
CDSC WAIVERS
Effective December 1, 1998 the "REDEMPTIONS OF SHARES--What Price Do I Receive
for Redeemed Shares?--CDSC Waivers" section in the Prospectus is supplemented as
follows:
CDSC WAIVERS. We will waive the CDSC payable upon redemptions of shares
which you purchased after June 27, 1995 for:
- - redemptions made within one year after the death of a shareholder or
registered joint owner
- - minimum required distributions made from an IRA or other individual
retirement plan account after you reach age 70 1/2
- - involuntary redemptions made by the Fund
- - redemptions limited to 10% per year of the account's NAV. For example, if
you maintain an annual balance of $10,000 you can redeem up to $1,000
annually free of charge.
We will waive the CDSC payable upon redemptions of shares which you
purchased after December 1, 1998 for:
- - redemptions made from an IRA or other individual retirement plan account
established through Comerica Securities, Inc. after you reach age 59 1/2
and after the eighteen month anniversary of the purchase of Fund shares.
<PAGE>
THE MUNDER FUNDS
SUPPLEMENT DATED DECEMBER 21, 1998
TO PROSPECTUS DATED OCTOBER 27, 1998
CLASS K SHARES OF:
THE MUNDER EQUITY SELECTION FUND
FUND INFORMATION
The "FUND INFORMATION--Goal and Principal Investments" section in the Prospectus
is deleted in its entirety and supplemented as follows:
GOAL AND PRINCIPAL INVESTMENTS. The Fund's goal is to provide long-term
capital appreciation.
- - Under normal market conditions, the Fund will invest at least 65% of its
assets in Equity Securities. "Equity Securities" include common stocks,
preferred stocks, warrants and other securities convertible into common
stock, including convertible bonds and convertible preferred stock.
- - The Advisor's dedicated research team invests the Fund's assets in Equity
Securities which it believes are undervalued compared to stocks of other
companies in the same industry.
- - The Fund generally invests in issuers with market capitalizations of at
least $1 billion.
- - The Fund diversifies its assets by industry in approximately the same
weightings as those of the Standard & Poor's 500 Composite Stock Price
Index ("S&P 500").
<PAGE>
THE MUNDER FUNDS
SUPPLEMENT DATED DECEMBER 21, 1998
TO PROSPECTUS DATED OCTOBER 27, 1998
CLASS Y SHARES OF:
THE MUNDER EQUITY SELECTION FUND
FUND INFORMATION
The "FUND INFORMATION--Goal and Principal Investments" section in the Prospectus
is deleted in its entirety and supplemented as follows:
GOAL AND PRINCIPAL INVESTMENTS. The Fund's goal is to provide long-term
capital appreciation.
- - Under normal market conditions, the Fund will invest at least 65% of its
assets in Equity Securities. "Equity Securities" include common stocks,
preferred stocks, warrants and other securities convertible into common
stock, including convertible bonds and convertible preferred stock.
- - The Advisor's dedicated research team invests the Fund's assets in Equity
Securities which it believes are undervalued compared to stocks of other
companies in the same industry.
- - The Fund generally invests in issuers with market capitalizations of at
least $1 billion.
- - The Fund diversifies its assets by industry in approximately the same
weightings as those of the Standard & Poor's 500 Composite Stock Price
Index ("S&P 500").
<PAGE>
THIS SUPPLEMENT SUPERCEDES ALL PRIOR SUPPLEMENTS
THE MUNDER FUNDS
SUPPLEMENT DATED DECEMBER 21, 1998
TO PROSPECTUS DATED OCTOBER 27, 1998
CLASS A AND B SHARES OF:
MUNDER ALL-SEASON CONSERVATIVE FUND, MUNDER ALL-SEASON MODERATE FUND AND
MUNDER ALL-SEASON AGGRESSIVE FUND
The "FUND CHOICES--What are the Underlying Funds' Investments and Investment
Practices? --Goal and Principal Investments for Equity Selection Fund" section
in the Prospectus is deleted in its entirety and supplemented as follows:
EQUITY SELECTION FUND
GOAL AND PRINCIPAL INVESTMENTS. The Fund's goal is to provide long-term
capital appreciation.
- - Under normal market conditions, the Fund will invest at least 65% of its
assets in Equity Securities. "Equity Securities" include common stocks,
preferred stocks, warrants and other securities convertible into common
stock, including convertible bonds and convertible preferred stock.
- - The Advisor's dedicated research team invests the Fund's assets in Equity
Securities which it believes are undervalued compared to stocks of other
companies in the same industry.
- - The Fund generally invests in issuers with market capitalizations of at
least $1 billion.
- - The Fund diversifies its assets by industry in approximately the same
weightings as those of the Standard & Poor's 500 Composite Stock Price
Index ("S&P 500").
CDSC WAIVERS
Effective December 1, 1998 the "REDEMPTIONS OF SHARES--What Price Do I Receive
for Redeemed Shares?--CDSC Waivers" section in the Prospectus is supplemented as
follows:
CDSC WAIVERS. We will waive the CDSC payable upon redemptions of shares
for:
- - redemptions made within one year after the death of a shareholder or
registered joint owner
- - minimum required distributions made from an IRA or other individual
retirement plan account after you reach age 70 1/2
- - involuntary redemptions made by the Fund
- - redemptions limited to 10% per year of the account's NAV. For example, if
you maintain an annual balance of $10,000 you can redeem up to $1,000
annually free of charge.
We will waive the CDSC payable upon redemptions of shares which you
purchased after December 1, 1998 for:
- - redemptions made from an IRA or other individual retirement plan account
established through Comerica Securities, Inc. after you reach age 59 1/2
and after the eighteen month anniversary of the purchase of Fund shares.
<PAGE>
THE MUNDER FUNDS
SUPPLEMENT DATED DECEMBER 21, 1998
TO PROSPECTUS DATED OCTOBER 27, 1998
CLASS Y SHARES OF:
MUNDER ALL-SEASON CONSERVATIVE FUND, MUNDER ALL-SEASON MODERATE FUND AND
MUNDER ALL-SEASON AGGRESSIVE FUND
The "FUND CHOICES--What are the Underlying Funds' Investments and Investment
Practices? --Goal and Principal Investments for Equity Selection Fund" section
in the Prospectus is deleted in its entirety and supplemented as follows:
EQUITY SELECTION FUND
GOAL AND PRINCIPAL INVESTMENTS. The Fund's goal is to provide long-term
capital appreciation.
- - Under normal market conditions, the Fund will invest at least 65% of its
assets in Equity Securities. "Equity Securities" include common stocks,
preferred stocks, warrants and other securities convertible into common
stock, including convertible bonds and convertible preferred stock.
- - The Advisor's dedicated research team invests the Fund's assets in Equity
Securities which it believes are undervalued compared to stocks of other
companies in the same industry.
- - The Fund generally invests in issuers with market capitalizations of at
least $1 billion.
- - The Fund diversifies its assets by industry in approximately the same
weightings as those of the Standard & Poor's 500 Composite Stock Price
Index ("S&P 500").
