A stop loss order was entered on a stock account.  The stock was
tlater transferred to a new account number and name, a trust accout - 
 a new stop loss order was not signed with the new account number. 
The firm executed the original order saying they transferred it to the
old account.  Nothing had changed except the designation of the
account as a trust account and the account numer.  All issues were
transferred from the old account.  My question is I would like to
rescind the trtade based on the fact I did not sign a new order
withtthe new account name and number,  can I???

If the account was fully transferred into the trust and the broker
made a good faith effort to alert you that all open orders would be
transferred as well, then you will not be able to "d-k" (e.g. trading
jargon for "don't know") the trade.

If on the other hand, 1) you instructed your broker only to do a
partial transfer of shares into your trust or 2) your broker did not
make a good faith effort to alert what particularly was transferred
(and failed to communicate to you what was transferred), then you have
a good chance at "d-k"ing the trade. This is true especially if you
broker did not send you in writing a trade blotter of what was
transferred (shares and share amount) and/or the open order that was
transferred. Particularly, this would apply to you if your broker has
a history of not communicating trades to you - and has thereby
demonstrated a track record of failing to fulfill his fiduciary duty
to you as the customer and account holder.