That's right, you'll get a lot of .NULL. fields when you do a FULL OUTER JOIN.
Which doesn't always make it useful.

So I gather that the result set you would want should look something like this?

(The first record is found left side only.
The second record is found right side only.
The third record is found both sides.)

SETTDATE   PORTFOLIO BANKNAME  NOFIND   FIND  TOTRECORDS  FINDRATE
------------------------------------------------------------------
{07/24/00} four      BankFour       1      0           1   100.000  
{07/24/00} one       BankOne        0      1           1     0.000 
{07/24/00} two       BankTwo        1      1           2    50.000 

To get this, you could do the following:

Select hitrate1.settdate, hitrate1.portfolio, hitrate1.bankname, ;
	COUNT(ISNULL(newmid)) AS nofind, 0 as find ;
	FROM hitrate1 ;
	WHERE ISNULL(newmid)=.T. ;
	GROUP BY bankname, settdate ;
UNION ;
Select hitrate1.settdate, hitrate1.portfolio, hitrate1.bankname, ;
	0 as nofind, COUNT(!ISNULL(newmid)) AS FIND ;
	FROM hitrate1 ;
	WHERE ISNULL(newmid)=.F. ;
	GROUP BY bankname, settdate ;
	INTO TABLE hitunion

Select bankname, portfolio, settdate, ;
	Sum(find) as find, Sum(nofind) as nofind ;
	from hitunion ;
	group by bankname, portfolio, settdate ;
	into table hitsums

Select *, (FIND+nofind) AS totrecords, ;
	(FIND/(FIND+nofind))*100 AS findrate ;
	FROM hitsums ;
	ORDER BY bankname, portfolio, settdate ;
	INTO TABLE hitrate4

HTH