(defun makefilehash (zips)
  (let ((h (make-hash-table :test 'equal)))
    (iter (for f in zips)
      (let ((year (getyear f))
            (month (getmonth f))
            (symbol (getsymbol f))
            (askbid (getaskbid f)))
        (unless (gethash askbid h)
          (setf (gethash askbid h) (make-hash-table :test 'equal)))
        (unless (gethash symbol (gethash askbid h))
          (setf (gethash symbol (gethash askbid h) (make-hash-table :test 'equal))))
        (unless (gethash year (gethash symbol (gethash askbid h)))
          (setf (gethash year (gethash symbol (gethash askbid h)) (make-hash-table :test 'equal))))
        (setf (gethash month (gethash year) (gethash symbol) (gethash askbid h)) f)
    h))