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.
Bid size and ask size indicate how many shares investors are looking to buy or sell at a specified price. Differences between the bid and ask sizes can provide valuable clues as to the short-term direction of a stock. A basic quote consists of bid and ask prices. Bid is the highest price at which you can sell; ask is the lowest price at which you can buy. For example, if XYZ is quoted at $27.13 bid, $27.28 ask, the highest price at which you can sell is $27.13, and the lowest price at which you can buy is $27.28.