OPPENHEIMER CAPITAL APPRECIATION FUND
                  Supplement dated September 25, 1998 to the
          Statement of Additional Information dated November 1, 1997


The supplement dated May 15, 1998 to the Statement of Additional  Information is
replaced by this supplement.


1. The  following  is added  after the  paragraph  captioned  "Risks of  Foreign
Securities" on page 13:

        Risks of Conversion to Euro. On January 1, 1999, eleven countries in the
       European  Monetary Union will adopt the euro as their official  currency.
       However,  their current currencies (for example, the franc, the mark, and
       the lire) will also  continue  in use until  January 1, 2002.  After that
       date, it is expected that only the euro will be used in those  countries.
       A common  currency is expected to confer some benefits in those  markets,
       by  consolidating  the  government  debt market for those  countries  and
       reducing some  currency  risks and costs.  But the  conversion to the new
       currency will affect the Fund operationally and also has potential risks,
       some of which are listed below.  Among other things,  the conversion will
       affect: o issuers in which the Fund invests, because of changes in the
      competitive  environment  from a consolidated  currency market and greater
      operational costs from converting to the new currency.  This might depress
      stock  values.  o vendors the Fund  depends on to carry out its  business,
      such as its Custodian (which holds the foreign  securities the Fund buys),
      the  Manager  (which  must price the Fund's  investments  to deal with the
      conversion  to the euro)  and  brokers,  foreign  markets  and  securities
      depositories.  If  they  are  not  prepared,  there  could  be  delays  in
      settlements  and  additional  costs to the Fund. o exchange  contracts and
      derivatives  that are  outstanding  during the transition to the euro. The
      lack of currency rate calculations between the affected currencies and the
      need to update the Fund's contracts could pose extra costs to the Fund.

The Manager is upgrading (at its expense) its computer and  bookkeeping  systems
to deal with the conversion. The Fund's Custodian has advised the Manager of its
plans to deal with the  conversion,  including  how it will  update  its  record
keeping systems and handle the  redenomination of outstanding  foreign debt. The
Fund's portfolio  manager will also monitor the effects of the conversion on the
issuers in which the Fund invests.  The possible  effect of these factors on the
Fund's  investments  cannot be determined  with certainty at this time, but they
may reduce the value of some of the Fund's holdings and increase its operational
costs.
                                                      [over]






2. The following is added to the third  paragraph in the section  titled "How to
Exchange Shares" on page 43:

      However,  shares of Oppenheimer Money Market Fund, Inc. purchased with the
      redemption  proceeds  of shares of other  mutual  funds  (other than funds
      managed by the Manager or its  subsidiaries)  redeemed  within the 30 days
      prior to that purchase may  subsequently  be exchanged for shares of other
      Oppenheimer  funds  without  being  subject to an  initial  or  contingent
      deferred  sales  charge,  whichever  is  applicable.  To qualify  for that
      privilege,   the  investor  or  the  investor's  dealer  must  notify  the
      Distributor  of  eligibility  for this privilege at the time the shares of
      Oppenheimer Money Market Fund, Inc. are purchased, and, if requested, must
      supply proof of entitlement to this privilege.

3. The fifth paragraph in the section  entitled AHow To Exchange Shares@ on page
43 is revised to read as follows:

      No contingent  deferred  sales charge is imposed on exchanges of shares of
      any  class  purchased  subject  to a  contingent  deferred  sales  charge.
      However,  if you redeem  Class A shares of the Fund that were  acquired by
      exchange of Class A shares of other Oppenheimer funds purchased subject to
      a Class A contingent  deferred sales charge within 18 months of the end of
      the calendar  month of the purchase of the exchanged  Class A shares,  the
      Class A contingent deferred sales charge is imposed on the redeemed shares
      (see "Class A Contingent  Deferred  Sales Charge" in the  Prospectus).  (A
      different  holding period may apply to shares  purchased  prior to June 1,
      1998). The Class B contingent  deferred sales charge is imposed on Class B
      shares  acquired by exchange if they are redeemed  within six years of the
      initial  purchase of the exchanged Class B shares.  The Class C contingent
      deferred sales charge is imposed on Class C shares acquired by exchange if
      they  are  redeemed  within  12  months  of the  initial  purchase  of the
      exchanged Class C shares.





September 25, 1998                                          px0320.005