A friend of yours trades stocks based on confidential information he overhears at his work. He even told you once that this information is not available to the general public. However, he keeps complaining to you that he can never make any profit on his stock trades. Based on this, you can argue that the stock market is ___ form efficient.

		semi-strong or strong
		either weak, semi-strong, or strong
		weak or semi-strong
		more than semi-strong
		weak or strong
		no more than weak