Can you not then just coalesce the values, sorry am not really clear on what relation p2 or p3 is to the buy or sell column, so I will assume they relate to sell proc sql;      create table WANT as      select     CUSPID,                    sum(BUY) as BUY,                    sum(coalesce(P2,P3,SELL)) as SELL,                    sum(BUY) - sum(coalesce(P2,P3,SELL) as BUY_SELL      from        HAVE      group by CUSPID; quit; Another tip is to normalise your data, i.e. rather than having columns for each bit, have rows, and an identifier column: CUSPID     DATE          ID          RESULT 0011          11jan12        BUY      0.3453525 0011          11jan12        P2         0.45564 ... It makes it easier to do aggregates. ... View more