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<PAGE> PAGE 2
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<PAGE> PAGE 3
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<PAGE> PAGE 9
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<PAGE> PAGE 13
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<PAGE> PAGE 16
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SIGNATURE STEVE LEMIRE
TITLE SECRETARY
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<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM
JUNE 30, 1998 SEMI-ANNUAL REPORT AND IS QUALIFIED IN ITS ENTIRETY
BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
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<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM
JUNE 30, 1998 SEMI-ANNUAL REPORT AND IS QUALIFIED IN ITS ENTIRETY
BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<SERIES>
<NUMBER> 3
<NAME> OBERWEIS MID-CAP PORTFOLIO
<MULTIPLIER> 1,000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-1998
<PERIOD-START> JAN-01-1998
<PERIOD-END> JUN-30-1998
<INVESTMENTS-AT-COST> 5,010
<INVESTMENTS-AT-VALUE> 6,592
<RECEIVABLES> 102
<ASSETS-OTHER> 40
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 6,734
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 54
<TOTAL-LIABILITIES> 54
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 5,303
<SHARES-COMMON-STOCK> 548
<SHARES-COMMON-PRIOR> 604
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (204)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 1,581
<NET-ASSETS> 6,680
<DIVIDEND-INCOME> 1
<INTEREST-INCOME> 2
<OTHER-INCOME> 0
<EXPENSES-NET> 66
<NET-INVESTMENT-INCOME> (63)
<REALIZED-GAINS-CURRENT> 21
<APPREC-INCREASE-CURRENT> 999
<NET-CHANGE-FROM-OPS> 957
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 71
<NUMBER-OF-SHARES-REDEEMED> (127)
<SHARES-REINVESTED> 0
<NET-CHANGE-IN-ASSETS> 333
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 13
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 85
<AVERAGE-NET-ASSETS> 6,652
<PER-SHARE-NAV-BEGIN> 10.51
<PER-SHARE-NII> (.10)
<PER-SHARE-GAIN-APPREC> 1.78
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 12.19
<EXPENSE-RATIO> 2.00
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
