Yes, do both. I would do BA first (because the 100K promo ends today) and then CO (before their promo expires). I applied for CO roughly 2 months ago and was approved with deferred approval. I applied for BA a month later and was also approved with deferred approval. I already had 3 other chase cards including the UA card at the time. I also applied and was approved with deferred approval for the Capital One Venture card between the two Chase applications, and that application wasn't inquiry friendly, but I was still approved for all the cards. I do have pretty good credit scores (other than the numerious inquiries) so I think that is the key.