WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000746714
<NAME> MUNDER LIQUIDITY PLUS MONEY MARKET FUND
<SERIES>
<NUMBER> 055
<NAME> CLASS Y
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-START> JAN-1-2000
<PERIOD-END> JUN-30-2000
<INVESTMENTS-AT-COST> 107914103
<INVESTMENTS-AT-VALUE> 107914103
<RECEIVABLES> 365686
<ASSETS-OTHER> 13432
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 108293221
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 851935
<TOTAL-LIABILITIES> 851935
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 107441409
<SHARES-COMMON-STOCK> 107441409
<SHARES-COMMON-PRIOR> 109550886
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> (123)
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 107441286
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 3431508
<OTHER-INCOME> 0
<EXPENSES-NET> (563746)
<NET-INVESTMENT-INCOME> 2867762
<REALIZED-GAINS-CURRENT> 0
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 2867762
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (2867762)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 86013167
<NUMBER-OF-SHARES-REDEEMED> (90989838)
<SHARES-REINVESTED> 2867194
<NET-CHANGE-IN-ASSETS> (2109477)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> (123)
<GROSS-ADVISORY-FEES> 197000
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 564000
<AVERAGE-NET-ASSETS> 113251000
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> 0.03
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> (0.03)
<PER-SHARE-DISTRIBUTIONS> 0.00
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> 1.00
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
