<PAGE>
Pursuant to Rule No. 497(d)
Registration No. 333-31247
DIAMONDS Trust, Series I
(A Unit Investment Trust)
SUPPLEMENT DATED MARCH 27, 2000
TO PROSPECTUS DATED FEBRUARY 28, 2000
Effective March 1, 2000, the Trustee has agreed to contractually reduce, on
a permanent basis, the Trustee Fees. The "Estimated Trust Annual Ordinary Op-
erating Expenses" table on page A-4 is hereby revised to indicate that the
Trustee's Fee is reduced from 0.1460 % of average daily net assets to 0.0963 %
of average daily net assets.
As a result of this fee reduction, the "Trustee Fee Scale" table on page B-
58 is hereby revised as follows:
TRUSTEE FEE SCALE
<TABLE>
<CAPTION>
Net Asset Value of the
Trust Fee as a Percentage of Net Asset Value of the Trust
- ---------------------- ----------------------------------------------------------
<S> <C>
$0-$499,999,999......... 10/100 of 1% per annum plus or minus the Adjustment Amount
$500,000,000-
$2,499,999,999......... 8/100 of 1% per annum plus or minus the Adjustment Amount
$2,500,000,000 and
above.................. 6/100 of 1% per annum plus or minus the Adjustment Amount
</TABLE>
