<TABLE> <S> <C>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM OPTIMARK
HOLDINGS, INC. (FORMERLY OPTIMARK TECHNOLOGIES, INC.) AND SUBSIDIARIES
CONSOLIDATED FINANCIAL STATEMENTS AT DECEMBER 31, 1999 AND 1998 AND FOR THE
YEARS ENDED DECEMBER 31, 1999, 1998, 1997, AND INDEPENDENT AUDITORS' REPORT AND
FOR THE UNAUDITED INTERIM PERIOD AT MARCH 31, 2000 AND FOR THE UNAUDITED THREE
MONTHS ENDED MARCH 31, 2000.
</LEGEND>
<S> <C> <C> <C> <C>
<PERIOD-TYPE> 3-MOS YEAR YEAR YEAR
<FISCAL-YEAR-END> DEC-31-2000 DEC-31-1999 DEC-31-1998 DEC-31-1997
<PERIOD-END> MAR-31-2000 DEC-31-1999 DEC-31-1998 DEC-31-1997
<CASH> 39,576,288 62,637,410 63,839,270 0
<SECURITIES> 1,373,750 0 0 0
<RECEIVABLES> 3,539,823 151,302 0 0
<ALLOWANCES> 0 0 0 0
<INVENTORY> 0 0 0 0
<CURRENT-ASSETS> 48,927,823 68,450,854 65,853,819 0
<PP&E> 27,745,692 27,871,913 10,457,131 0
<DEPRECIATION> 9,856,249 7,904,549 1,833,700 0
<TOTAL-ASSETS> 106,522,849 129,680,107 75,458,361 0
<CURRENT-LIABILITIES> 17,023,654 18,216,760 12,765,254 0
<BONDS> 0 0 0 0
0 0 0 0
227,221 229,721 145,471 0
<COMMON> 366,047 364,961 315,589 0
<OTHER-SE> 85,099,185 105,930,078 58,857,767 0
<TOTAL-LIABILITY-AND-EQUITY> 106,522,849 129,680,107 75,458,361 0
<SALES> 0 0 0 0
<TOTAL-REVENUES> 3,078,772 3,012,244 0 0
<CGS> 0 0 0 0
<TOTAL-COSTS> 9,722,398 40,457,202 24,667,218 4,171,720
<OTHER-EXPENSES> 16,674,881 100,500,549 34,452,166 16,834,192
<LOSS-PROVISION> 0 0 0 0
<INTEREST-EXPENSE> 273,097 1,079,554 321,798 0
<INCOME-PRETAX> (22,834,676) (35,078,509) (57,207,095) (20,443,546)
<INCOME-TAX> 0 0 0 0
<INCOME-CONTINUING> (22,834,676) (35,078,509) (57,207,095) (20,443,546)
<DISCONTINUED> 0 0 0 0
<EXTRAORDINARY> 0 0 0 0
<CHANGES> 0 0 0 0
<NET-INCOME> (22,834,676) (35,078,509) (57,207,095) (20,443,546)
<EPS-BASIC> (0.33) (2.12) (1.13) (0.54)
<EPS-DILUTED> (0.33) (2.12) (1.13) (0.54)
</TABLE>