During the period for securities underwritten on an agency basis or on a sole agency basis , securities firms shall ensure that such securities are first sold to subscribers . securities firms may not reserve , in advance , for themselves securities which they underwrite as agents , or purchase , in advance , and retain securities which they underwrite as the sole agents 證券公司在代銷包銷期內(nèi),對所代銷包銷的證券應(yīng)當保證先行出售給認購人,證券公司不得為本公司事先預(yù)留所代銷的證券和預(yù)先購入并留存所包銷的證券。