Cardiac tamponade can occur due to: 1  Dissecting aortic aneurysm (thoracic) 2  End-stage lung cancer. 3  Heart attack (acute MI) 4  Heart surgery. 5  Pericarditis caused by bacterial or viral infections. 6  Wounds to the heart.
Bid vs. ask and why yields matter. With many investments, the concept of bid and ask applies to prices. The bid price is what a buyer is willing to pay for a security, while the ask price is what a seller is willing to accept for the same security. The difference between those two numbers is known as the bid-ask spread, and in general, the narrower that spread, the more liquid the market is.
A bid price â usually referred to simply as the bid â is the highest price that a buyer (i.e., bidder) is willing to pay for the security. Ask price â also called offer price, asking price, or simply offer or ask â is the lowest price a seller will accept for the security. These prices are rarely the same: the ask price is usually higher than the bid price.